I use a g29 and as far as I am aware there are a couple of addons that can be downloaded for the LEDs to work, but out of two programs that I have tried they are rather buggy and very manual to setup, there is little automation and not very good car support as only the older vehicles worked, it was also impossible for me to save the values of each car's rev match and I would have to redoit every time I opened the program. Is this something difficult to incorporate in LFS? (I don't know much about programming)
Thanks

If somebody haven't made this already, than prob. belongs to https://www.lfs.net/forum/137-Program---InSim-requests, I can maybe take this, but we would need to switch over to discord for easier beta testing, as I don't have logitech products myself, so it would make debugging bit hard if only done throught lfsforums.

Also, did you checked this? https://www.lfs.net/forum/thread/68510
And: https://fanaleds.com/

(well, would be usefull if you would post the two solutions you've tried to make work)