Anything needs to be demonstrated and used in practice before being included in the standard. The standard is only meant to codify existing practices, not introduce new ideas.
It's up to compiler developers to ship first, standardize later.
So the best hope is probably for a third party library that has safet APIs to get popular enough that it becomes a de facto standard.
I don't have any clue how to patch clang's front end. I'm not a language or compiler person. I just want to make stuff better. There needs to be a playground for people like me, and hopefully lib0xc can be that playground.