If you want a good excuse to not do the scallops, the quilt is very angular as it is and the straight line keeps true with that.
How about a compromise and only curve the corners? That way you can try the technique and not drive yourself crazy. Besides, those corner curves are easy, it's the going back up again at the valley that is my tough spot.
The curves do require a bit of fussy and fudging as you go through but it isn't too bad. Didn't really add any time when I've done it but I'm super slow on handwork, I'm not very good at it, and with my vision issues I get cranky! I do as little handwork as I possibly can, but I still put my binding on the front by machine and flip and do the invisible stitch back because I am happiest with the way that comes out.