Thanks, Split. We really don’t want to record the solo at a flat tempo or to a click track though, which I think is what you may be suggesting?
What I’ve done is put a clearly visibly identifiable tempo change on a beat at the very end of the project. Then, after I’ve recording the solo in the middle of the project, I manually adjust the subsequent tempo points (point by point, manually editing) until everything lines up again at the end. Very tedious, and easy to mess up if one loses focus for even a moment.
Surely there’s a better way?