They said a few times they are working on documentation for the new materials and pbr for mods. So why the "maybe"?
They have been "working" on documentation and information updates for years, yes there were a couple of physics blogs that didn't cover a lot of stuff and some painting tutorials, but that is it. There are lines in the physics and tyre files that aren't even mentioned in documentation anywhere, and no specific details about what changes in the updates do or sometimes even what they changed. The spreadsheet is all well and good, if you can understand it, but fails to provide information about what stuff is or what data range is appropriate. You have to work it out yourself.
Making content for rF2 is the hardest game to do, it has the most complex physics, most restrictions on how the shaders interact with the model objects (like no damage on debris objects), tyres that even engineers have trouble understanding and yet there is a lot of documentation that is either redundant or missing. Further making things difficult, they don't support troubleshooting for 3rd party content, meaning we have to work it out through trial and error. The forum here can be useful, but only by other members, and discord is almost as bad if not worse. There is also a distinct lack of example files which can make things a lot easier to understand, even their own content doesn't follow the current dev guide in many circumstances unless it is paid content.
I have put in well over 3,000 hours in creating a mod and love the game, it has just been a lot harder than it needed to be. Having to rebuild stuff and spend many hours troubleshooting things that could have been avoided by having decent documentation or having a question answered on here.
Here is a simple question. Why have features in a game if people aren't able to make content that fully make use of those features?