Suggestion: Use ADRs instead of or in addition to RFCs.

[JalonSolov]

ADR == Architectural Decision Record

Read all about them here: https://adr.github.io/

Actually, I prefer the variant of MADR: https://adr.github.io/madr/ - which is just ADRs in Markdown format.

The advantage is they are reasonably well defined, including how to manage changes to the decisions.

An ADR with "Status: proposed" fulfills the same role as an RFC, in that it gives a proposal for an idea that others can then comment upon.