I know I’m not the brightest person

Never put yourself down!

If a Goblins implementation in Rust would effectively be useless

Not saying it would be useless, I’m saying I don’t understand what you mean. Certainly a high-level API on top of OCapN would be useful. Goblins, afaiu, is a guile library. Given that there can’t be a 1-1 correspondence between the API, it is unclear what would a Goblins in Rust would look like. Have you written some [non-working] example code to give a more concrete idea of what you are looking to implement?

I’m confused, why do you say Goblins in Rust instead of a Rust implementation of OCapN. Do you intend to copy the API itself? A Rust implementation OCapN would be indeed useful. It would allow the system to have different parts implemented in different languages. But a Goblin in Rust doesn’t even have a clear meaning API-wise.