Soft Keywords and How to Implement Them

I've been thinking for a day about how we can possibly implement [PEP 622]() in case of acceptance. While I was thinking, I drafted a piece of code, which might seem totally unreasonable (since it changes the parser to semi-LL(1) from LL(1)) but wanted to share it as a maybe last resort? I tried to document the strategy as inline comments, so feel free to read and comment about it:

https://github.com/davidhalter/parso/compare/master...isidentical:soft-keywords-very-very-bad-demo?expand=1