T2 manages to do it

https://t2linux.com/

Yocto, which we use at work, manages it just fine to build a whole embedded Linux distro. So I don't see why Fedora couldn't make it work if they wanted. You could even scp over the test suites to run that on native systems if you wanted.

Maybe there are issues I'm not aware of but using dockcross has made cross-compilation quite easy in my experience.

https://github.com/dockcross/dockcross

Depends on the language, it's pretty trivial with Go.