Both GNU and GrapheneOS have staunch requirements and will accept no compromises.
This is a situation where their requirements don’t align, so they’ll never reach an agreement.
GrapheneOS, for example, is also strictly against making the Fairphone line of phones a little more secure because it doesn’t meet all of their security requirements
In this case GNU won’t certify GrapheneOS as fully open because it includes binaries that aren’t open
The FSF is more along your line of improving the situation where they can
In those cases, they generally have the Ubuntu version that’s supported in the specs section