However,
I'm a bit old-school.
I want, in my home, entertainment devices to be quiet, energy efficient and lossless as much as possible. And per cent, of course.
So,
this issue still bothers me.
Well, not so much now, with the USB power control workaround... 
But inputstream/widevine failure to achieve flawless 720p playback, while S905x boxes can... This I cannot forgive on S912. Putting the box back in the drawer as cold spare...
Because it'll burn down velqn's house to the ground... 
After some more testing with my S905/S905X/S912 boxes - I stand corrected.
Two Philips TV sets are able to power the boxes from USB power feed ONLY.
So,
the workaround with TV set, controlling the box via USB power, is absolutely applicable,
on one condition: no other USB power-hungry devices attached to the box.
And - on S912 Android is not able to operate - not enough power, LE is working, though...
Therefore,
there are two feasable workarounds for the H96Pro+ S912 boxes at the moment:
1. Reboot from LE to Android and power off/on
2. Power the box from TV USB port via USB A-to-A cable. When you switch off the box, the CEC will switch off TV, AV receiver(s) and etc.
When you power on the TV (AV receiver) - the box will be powered on automatically and, presumably, boot into LE.
Bare in mind that power feed USB port on H96Pro+ boxes might be only one - discover it empirically. 
and
3. zed85 provides information for the ROM with working boot/u-boot, users test it, if it works - we all flash this boot/u-boot.
Happy! 
It seems that's all, folks.
For now...
So,
your current situation is:
- booting LE from SD/TF card
- Android ROM is broken, cannot load
Would you be willing to check some things in the Android ROM via LE?
For example,
once the LE has booted,
check whether the internal partitions are visible:
H96:~ # blkid
/dev/loop0: TYPE="squashfs"
/dev/cache: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/tee: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/system: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/data: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/mmcblk1: PTUUID="70347706" PTTYPE="dos"
/dev/mmcblk1p1: SEC_TYPE="msdos" LABEL="LIBREELEC" UUID="2301-1436" TYPE="vfat" PARTUUID="70347706-01"
/dev/mmcblk1p2: LABEL="STORAGE" UUID="8fbb1db9-b05f-4805-a71c-9ce8a0989c23" TYPE="ext4" PARTUUID="70347706-02"
/dev/sda1: LABEL="WD500" UUID="04C04E181F1814A1" TYPE="ntfs" PARTUUID="f1961b10-01"Then:
H96:~ # mkdir /media/system
H96:~ # mount /dev/system /media/systemAnd get us the "build.prop" contents, for starters:
H96:~ # cat /media/system/build.propOr if you can copy the whole build.prop file and attach it here to review it - it will be best.
This will show us the version of your broken Android ROM, to look for it and test its boot/u-boot.
Your assistance is much appreciated! 
Your workaround might be valid for not that power-hungry USB dongles.
But for an H96Pro+ box, performance boosted, we need:
Nevertheless,
it's a good hint, so users should test this on their setups, did not work on mine, but it's a bit proprietary.
TV controlling the box power via USB is a workaround, if the power...
The reference was deliberate...
Nope.
The important point is that ROM version is lost into oblivion now.
And I'm sure that the user is not able to extract the current boot.img (u-boot).
All is lost here...
And who wants Android as base for Mediacenter really?!😉
With the current state of LE (regardless 8.x, 9.x) for S912 (H96Pro+), I do NOT see any benefits in running it on such box, in comparison to properly tuned Android 7.1.2 ROM.
In fact - I've recently switched back to Android and it suits my needs perfectly fine.
Just bare in mind - this is a special case (my case): H96Pro+ (S912)...
Sadly, but it will NOT work.
Most important thing here is the Android ROM with the "u-boot" component.
Not LE dtbs and remote.confs...
I told you already - my setup(s) are scripted to mount the network resources locally per each UX.
# systemctl stop kodi
# rm -rf .kodi/addons/inputstream.adaptive
# rm -rf .kodi/addons/rtmp.input
# systemctl start kodi
or
# reboot
Can't help about the tvheadend, not using it...
Good luck!
And does any good solution come from these users?
Link to the Android ROM, containing the "proper" u-boot part, which will fix this infamous issue?
Yes.
H96Pro+ is definitely not recommended for "internal" installation, at least at this stage... 
From LE you have to reboot to internal (Android) and then power off. 
If you're using a different than the default skin (Estuary/Estouchy or whatever @#?! it was),
check this to create a custom shortcut for that function.
I guess (almost) nobody was aware when bought the box...
It simply was NOT built to run LE OOB (out-of-the-box).
I find it puzzling that your box does not automatically boot into LE from the placed SD/TF card, each time it has been powered on.
Maybe you're "fake" powering off your Android.
Check the power button settings in Android and set it to REALLY power off the box, not sleep/suspend it.
Mine does exactly that.
We (H96Pro+) all have this problem.
Current workaround is to reboot to Android and power off there. Then you can power it on from the remote, and if the SD/TF card with LE is in place - it will boot straight to LE...
Because of *#@?! TV manufacturers, which have forsaken the support for older than 2016 models and there - no passthrough, no multichannel and etc. I am not going to replace the HW of my TV each year.
And why not "All-In-One" box concept?
