The prism (npub1arc…ggtw) guys with bob (npub1cd0…xlvx) and gudnuf (npub1ce7…3d7m) are sending huge zap splits with Cashu afaik.
A single payment is instant, could you just send n payments and that's it? Thinking of PABLOF7z (npub1l2v…ajft)'s new invention (notice how I avoid the name nutsack), you could send multiple note events with ecash and you should be good.
Can you explain the use case in more detail?