Just adding that rfactor 2 plugin is working in Le mans Ultimate.
https://www.youtube.com/watch?v=uH2oZW6ilSE
Here are some info from le mans ultimate forums.
"Well, I just did the test by renaming
Le Mans Ultimate.exe (with space!) to rFactor2.exe, so it actually works but obviously there is a problem impossible to launch by Steam you have to go through the game icon on the desktop, and especially now that I changed the name Simtools no longer works and my dynamic 2dof simukit does not detect anything. and impossible to launch it manually so this solution is not viable for me"