F1Fanb0y HiassofT thank you so much for the update. I installed and let the agents debug the issue. Basically I pointed a webcam to the Slice with CM3 , covered all or it so was all dark and instructed to keep trying until you see the light. It took some time and at the end: et voila', LEDs are working.
Have a look at this PR: https://github.com/4nvjgf39/LibreELEC.tv/pull/1. There was also an issue mounting the internal HDD that was not visible on reboot.
I tired on Slice with CM3 and works like the old libreelc. Let me know if questions.
my Red Slice. It's a very well design product, it feel like a premium device next to the TV.