nostr:npub10000000thpep7auj058803nqtymqlf3rw87lzhe6mkfeywnpxg5sjw7nql you familiar with this?
If you know the split up front you can actually just broadcast the note with all of the participants in zap tags with their respective weights
https://github.com/nostr-protocol/nips/blob/master/57.md#appendix-g-zap-tag-on-other-events
nostr:npub10000000thpep7auj058803nqtymqlf3rw87lzhe6mkfeywnpxg5sjw7nql you familiar with this?