Do you know of any (talented) Bitcoin devs in need of funding that are working on a cross input signature aggregation BIP? The only progress I know of is what I heard from Jonas Nick & Tim Ruffing when they appeared on Stephan Livera's podcast (ep 400).
Discussion
Sorry, I'm not aware of anyone working on that.
I'm personally working on a Compact Block Filters (BIP157) client in Rust. Too many wallets rely on centralized backends or require complicated setups where you have to run a full node if you want to be private (most plebs can't/won't do it).