Well, forget the libraries and double check your configuration again instead.
Why don't you try the same (earlier working on RPi OS) display settings in LCDd.conf?
I see you changed the Speed parameter from 19200 Bd to 115200. Some displays have the DIP switch to select the preferred speed so if you did not set that properly, the garbage on your display is the logical result.
OK, I understand. So please don't mix too many things together and focus on LE.
I think LCDproc works on LE as same as on Rpi OS if properly configured, just the config file location / driver folder location is different. I can recommend to do / check these steps in LE:
1) Put the appropriate necessary options to /flash/config.txt and check if the display is properly attached, check if there's no HW / SW conflict on UART
2) Install the LCDproc add-on and configure it in GUI to select the correct driver. Then reboot LE and check if the LCDd is running with proper parameters using ps | grep LCD
3) Edit the appropriate LCDd.conf config file located in accordance with ps | grep LCD output to put necessary preferrences to correct display section
4) Reboot LE again and then install and configure the XBMC LCDproc add-on properly.
I don't have any experience with Cfontz display as I am using hd44780 connected through i2c but I believe it should work fine as well.
You can also run the LCDd in foreground to test quickly with any preferred config file but make sure you don't run more instances at the same time.
Yes as you can see in your PS output there's the -d hd44780 parameter which forces this driver to be used (see the comments at beginning of LCDd.conf file regarding to -d parameter).
Change that in LCDproc add-on Configuration settings first to use another (CFontz or whatever you like) instead of default hd44780 driver.
Hopefully it's not a feature of Kodi 19.0-BETA1 as the screenshot filename's structure has been changed a bit but I couldn't find more info / fresh documentation related.
Action taken while TV playing:
kodi-send --action="Screenshot"
or
kodi-send --action="TakeScreenshot"
or invoked by keyboard (CTRL+S or PrtScr)
The screenshots are made in /storage/screenshots/ folder but...
Currently the Screenshot / TakeScreenshot action does not put the active video frame snapshot to .png file, just the Kodi's active GUI menu or a just black page if no menu is active.
Screenshot names are now starting from:
screenshot00000.png
Everything worked as expected (and documented) in LE 9.2.6 official with Kodi 18.9.0 - if the Screenshot was taken, there's a picture frame (combined with active Kodi GUI menu ) saved to .png file.
Screenshot names were starting from:
screenshot000.png
So you need to edit the [hd44780] section in /storage/.kodi/userdata/addon_data/http://service.lcdd/LCDd.conf to match your specific UART display's HW.
You may also find some info here:
Run this command to see what's the path to current LCDd.conf:
ps | grep LCD
You should see there something like:
LCDd -f -c /storage/.kodi/userdata/addon_data/http://service.lcdd/LCDd.conf -d hd44780
I have found some How To's and tried to create .pls and .strm files to be opened from Videos menu. Unfortunately so far I couldn't finish that simple task succesfully. 
The stream (MJPG 640x480, Planar 4:2:2 YUV full scale) is produced by ESP32CAM module using this source code: esp32-cam-mjpeg-multiclient/esp32_camera_mjpeg_multiclient.ino at master · arkhipenko/esp32-cam-mjpeg-multiclient · GitHub
It works fine with Firefox, Chrome, Edge and VLC but no way from Kodi.
Files tested:
cam1.pls
[playlist]
NumberOfEntries=1
File1=http://192.168.35.201/mjpeg/1
Title1=IP Camera
cam1.strm
Debug log when tried to open first the cam1.pls and then cam1.strm file:
Am I doing something wrong or there's a bug?
Thanks for the reply. Yeah but even the display clone I can't achieve on LE 9.80 - the display content is cloned when LE starts (the LibreELEC logo displayed on both ) until Kodi is initialitzed - then the secondary display is blanked out (regardless the Blank other displays settings) until Kodi is stopped - then the LE logo is again visible on both displays.
FYI this is info from Raspberry OS on the same HW:
export DISPLAY=:0.0
xrandr
xrandr
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 7680 x 7680
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 160mm x 90mm
1920x1080 60.00*+ 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1920x1080i 60.00 50.00 59.94
1600x1200 60.00
1680x1050 59.88
1280x1024 75.02 60.02
1440x900 74.98 59.90
1280x960 60.00
1280x800 59.91
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
HDMI-2 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 1150mm x 650mm
1920x1080 60.00*+ 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1920x1080i 60.00 50.00 59.94
1280x1024 60.02
1360x768 60.02
1280x720 60.96 60.00 50.00 59.94
1024x768 60.00
800x600 60.32
720x576 50.00
720x576i 50.00
720x480 60.00 59.94
640x480 60.00 59.94
720x400 70.08
I know this question repeats now and then and looks even Kodi 19 BETA1 still does not support more than 1 display on this platform.
But I wonder if any developer could share some information what's the current status regarding this matter please? What is possible and what is not possible and why? Whay does and what does not make sense to try?
The goal for me in future is to use HDMI0 for LE / Kodi and HDMI1 to display IP camera(s) stream(s). Currently I am trying to get Kodi working on preferred HDMI port when there are 2 displays connected.
I have discovered that Kodi in LE 9.80 succesfully switch to HDMI port where the display is connected at boot if there's just 1 display connected. So HDMI1 can be used this way. But if both HDMI ports are occupied, always HDMI0 is used.
Is there any other way to force Kodi to use HDMI1 port instead default HDMI0 without cable detaching? The Monitor option is missing on Kodi Settings / System / Display page, playing with guisettings.xml did not help so far to overcome the default output to HDMI0.
On LE 9.2.6 using tvservice app (not useable anymore on LE 9.80) I was somehow able to get video displayed on HDMI1 even after boot when HDMI0 was active but there's no way to do the same on LE 9.80.
Struggling with config.txt in accordance with post Rpi4 - switching between different resolution HDMI outputs with one click also did not help.
xrandr does not work on LE 9.80 (yet?).
Could somebody informed give a comment please?
If you connect a display only to HDMI 1 port and upgrade to LE 9.80 nightly, Kodi will work - both audio and video goes to HDMI 1 automatically. When 2 monitors are connected, on both HDMI 0 and HDMI 1, Kodi works on HDMI 0 only.
So it should be yet possible to switch between HDMI 0 and HDMI 1 but I don't know what to configure. In Kodi / Settings / System / Display the option Monitor is missing even though I tried to play with the ~/.kodi/userdata/guisettings.xml modification, so far I failed to get the Kodi working with preferred HDMI port when both HDMI ports are occupied.
Also tried to modify the /flash/config.txt in accordance with this post Rpi4 - switching between different resolution HDMI outputs with one click but so far not succesfully.
Audio output on RPi 4B's HDMI1 works yet on LE 9.80 nightly.
OK, thanks a lot for a quick reply and sorry for "hoax"... 
FYI on LE 9.80 nightly builds ( LibreELEC-RPi4.arm-9.80-nightly-20201124-59085f2.tar ) which are using ALSA audio drivers it's possible to switch audio output (Kodi - Settings / System / Audio - Audio output device) to display connected to HDMI1 and it works fine.
But the option for audio output to Default Audio Device + HDMI together is missing.
It looks something is wrong as on the same RPi 4B HW configuration running LE 9.80 nightly (even latest 20201124) the tvservice command does not find any HDMI display connected in comparision with LE 9.2.6 official so it can't be used on LE 9.80 at all.
LE 9.80:
LE:~ # tvservice -l
0 attached device(s), display ID's are :
LE 9.2.6:
LE:~ # tvservice -l
2 attached device(s), display ID's are :
Display Number 2, type HDMI 0
Display Number 7, type HDMI 1
Well, I am using RPi4 and had no HDMI sound issue after upgrading LE to 9.2.6.
I don't think the onboard micro HDMI connector is broken, more likely it could be a cheap cable with bad contacts. But usually if there's a video OK, the audio also works ( AFAIK both goes through TMDS channels ).
At first I would check the TV / display attached if the audio is not muted / switched off there... Or if there are external speakers connected to display...
AFAIK the secondary HDMI port on RPI4 is not supported in LE. So far I did not have a reason to play with the settings (using just the HDMI 0 port) so I don't know what is possible to do...
Just quickly tested the tvservice command which partially works on LE 9.2.6 with issues (sometimes the -v parameter is ignored, sometimes it hangs etc.) on 2 HDMI displays connected and sometimes I was able to switch video to secondary HDMI port (using -p and -o parameters on both ports but don't ask me how exactly, it's hard to reproduce it). But just the video.without sound and without LE GUI.
There's -a parameter which should display info about audio supported so maybe you can try to play with this.
LE:~ # tvservice -l
2 attached device(s), display ID's are :
Display Number 2, type HDMI 0
Display Number 7, type HDMI 1
LE:~ # tvservice -a -v7
PCM supported: Max channels: 2, Max samplerate: 192kHz, Max samplesize 16 bits.
AC3 supported: Max channels: 6, Max samplerate: 48kHz, Max rate 2040 kb/s.
LE:~ # tvservice -a -v2
PCM supported: Max channels: 2, Max samplerate: 48kHz, Max samplesize 24 bits.
LE:~ # tvservice -s -v2
state 0xa [HDMI CUSTOM RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive
LE:~ # tvservice -s -v7
state 0xa [HDMI CEA (16) RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive
LE:~ #
Thanks for your comment, chewitt. Yes I know you are right. I don't know (and despite some searching couldn't find / discover) any details how the info labels (related to StreamSignal and StreamSNR) works (I did not analyze the source codes as it's above my level).
But I thought it could grab it from femon or dvb-fe-tool by a simple script. In this case it would be easy (for anyone) to make a modification but it looks it's not the case.
I absolutely understand that low priority of this issue but I think if there are still the Signal and SNR values present at PVR info page, it should show the valid values or tagged them as unsupported and get removed instead.
Anyway, I am happy with the simple solution outlined above, that's suitable for me (just improved the script example a bit and configured a mapping to IR remote key). BTW. the Notification command is very useful and I am using it also for CPU high temperature warning (as sometimes one or more cores stuck at 100%).
Well, as it's really hard to discover what issue are you facing to without any description (or without at least the command error output ),
I am afraid anybody can hardly help you...
Usually - AFAIK - you need to load the appropriate driver module without device ID parameter. If it loads OK (it could depend on other modules which needs to be loaded before), it should recognize the device.
lsmod
dmesg
modinfo RTL88x2BU.ko
command outputs could perhaps give a hint to you.
Perhaps you could edit or create the /storage/.config/autostart.sh file and put there something like this: insmod /PathToFile/RTL88x2BU.ko ?
