There is no reason I can think of that knitting the front bands before seaming wouldn't work. They aren't involved in the seaming in any way. Don't go only by what I think, please, wait for others who are more experienced to comment.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper