I just updated the Spreadsheets Draft NIP to support sharing encrypted spreadsheets with a group of pubkeys in both: read-only and read/write mode.

Now you can assemble a:
- Public View spreadsheet
- Encrypted Spreadsheet just for yourself.
- Encrypted Spreadsheet that only a few people can see.
- Encrypted Spreadsheet that a group of people can edit.

Sheetstr has not been updated yet, but I think this adds parity with all Google Spreadsheet's collab features.

Check it out:
https://github.com/nostr-protocol/nips/pull/1189