This is using btcd's (roasbeef) implementation of MuSig2, by the way. If it's broken complain to him.
An amazing video showing how you can sign notes cooperatively on nak using musig2, now with 3 signers instead of the boring 2 from the previous video:
https://cdn.satellite.earth/5c23f403972ce013e39c1878ac620bcc742031faa90280a01541f09e81f4b694.mp4
This is using btcd's (roasbeef) implementation of MuSig2, by the way. If it's broken complain to him.