I am totally new to Photoshop as of a couple of days ago when I became a Creative Cloud member.
So in brief, are you saying that anything pushed out by Photoshop is going to be a huge file and is unavoidable? If so I'll just have to suck on it. It's just if everything I ask it to do is going to give me a 1gb file then my hard disk space is sure going to run out quicker than I'd hoped.
From now on with stitching I'll use AutoPano which literally does just stitch them together and hand it back as in whatever format it was received and normal size too.