To build LE without Kodi is not that difficult, basically "just" a change that a console is started instead of kodi, an setup utility need to get written to setup LE (this could be done manually too but nobody really want that) and a bash/python "addon" download tool.
A barebone server version was already done, with some manual effort it is easily doable even today.
There was an RPi3 version (very stripped down) without kodi for some special software that was around 20-30mb in total.
Even the Youtube app doesn't work
for youtube you need to follow the steps mentioned for the addon Personal API Keys · jdf76/plugin.video.youtube Wiki · GitHub
thats a bit meh but just a one time thing for all of your devices (you can reuse the key multiple times)
I havent build Tvheadend for LE10 yet so there is no update yet. If you just want Tvheadend 4.2 then head over to Index of /builds/addons/RPi4/service.tvheadend42/
Just for reference, there is an open source YouTube client for Android which does not require API keys.
Everyone that uses the APi needs api keys, ofc you could include them into the addon. But like we already saw they expire really quick due the amount of users.
there is the libxcb-dri3.so.0, just copy it to the addon and reboot afterwards (or the system might not recognise it)
/storage/.kodi/addons/browser.chrome/lib/libxcb-dri3.so.0
not sure if this works for you
updated iInputstream addon is at our repo (9.2.0) since some hours ago, so pls have a look 
oh dear, the file alone won't fix it
looks like the new chrome version broke something else too, could take a while
LibreELEC:~ # ldd /storage/.kodi/addons/browser.chrome/chrome-bin/chrome | grep "not found"
libxcb-dri3.so.0 => not found
I can confirm it, try to get an fix on the way asap
I'm a little bit disappointed because after year rpi don't have these features.
Main problem is that basically nothing has proper HDR support yet (Vero, AML ... use vendor specific apis that are gone in K19) with an proper Kodi integration. Its getting there but not before Kodi19.
However using Live Channels with pass as stream profile is still fails.
The htsp Kodi Client wants the htsp profile, the HTSP Profile includes additional informations like EPG and stuff. The pass profile is for VLC and similar applications.
So it may not work at all. Transcoding works ofc too with kodi but then the RPi is too weak for it to do it properly and fast.
yes you can, RPi2 and RPi3 are basically identical, at least for LE
this is my kodi user (Tvheadend 4.3 so likely a bit different), at Change parameters: tick everything besides HTSP Output Format then the user should just work
if this is still not working we can manually remove usersettings and it might work again too (I need access to my pc to tell you the details later)
and
the settings at your Kodi for the pvr.hts (pvr.tvheadend) addon
can you
dmesg | paste
not sure for what I am looking at the moment
likely "a kodi" problem, a lot addons are fubar atm
did you checked that you are not using SMB1 (old Win XP Samba protocol) at your smb server ?!
when using a matroska stream profile
then you already partly transcode the stream, that is not what you want
sing pass only works for a few channels HD channells but appears to be slow as well.
this is the way to go, what means slow, 2sec? 10sec ?
can you do a screenshot of your settings ?
Btw pls also try Kodi at Windows if there are the same problems. The Shield should do it but you never know.
Normal switch speeds are around 2-3sec. Worst case is <5sec for a full channel switch.
