I have a lot of sympathy for this view, especially since 'hobby' platforms tend also to be those whose maintainers are doing it on the side and who are thus les

I have a lot of sympathy for this view, especially since 'hobby' platforms tend also to be those whose maintainers are doing it on the side and who are thus less likely to be keeping up with internal API and similar cross-codebase improvements. But it gets complicated when the project is a foundational one like LLVM, where dropping or not accepting support for an architecture is effectively also locking the architecture out from a wide swathe of other projects (for instance, Rust, and via Rust also Firefox). I think the best way to manage this seems to be to have an official 'tier list' with criteria and consequences for being in each tier (so for instance lower-tier ports might be in a "nobody else is expected to build/test this, failures are not a blocker for commits" grouping). That doesn't solve the problems, but it does at least mean everybody knows where they stand. (IIRC LLVM does have a tier list system but I haven't looked up the details.)