So apparently you don't need #UnRAR to extract #rar files because there are two #OpenSource projects that were made without proprietary bits.
1.) unrar-free is a maintained version of unrar-free from the Gna! CVS archive. It seems to only be able to do non-split rars but it should work.
2.) #unar is the command for extracting archives via #unarchiver. It works perfectly, the only thing is it uses different syntax than unrar so it is not a replacement via alias. (you can use the python wrapper I found to use it as a drop-in replacement.)
I used the wrapper to be a drop-in replacement and #patool found it and worked perfectly. (BTW patool is fucking amazing please use)
unrar-free: https://gitlab.com/bgermann/unrar-free
unarchiver: https://github.com/MacPaw/XADMaster
unar_wrapper: https://github.com/openSUSE/unrar_wrapper
patool: https://github.com/wummel/patool