One important feature of the MuSig2 design is that, though it's a 2-round protocol (round 1 share, nonces, round 2, share partial sigs), you can actually do the 1st round well ahead of time, without already knowing what message is to be signed. This enables a more compact one-round flow in actually signing in real time.

How that actually compares to status quo in terms of performance, assuming everything is set up correctly - I don't know. I'm sure there are a lot of fiddly details there.