I’ll also add that this proposal is very adjacent to Transient Storage, which is going into Cancun. I actually asked about this general idea on the Transient Storage thread a couple months ago.
The only real issue is that storing anything with Transient Storage triggers a function to become default (state changing) status, rather than remaining as a view function. I think if that issue was addressed, then Transient Storage would basically solve for what I’m talking about.
So the upshot is that maybe implementing this won’t be that hard. Or maybe it turns into just a small improvement/variation on the Transient Storage upgrade.