I can empathize with your sitting for long periods of time due to back issues. I find it difficult to sit or stand for more than 20 minutes due to back pain. So I chip away at the quilting fun buy cutting a short time and the. Sewing for a short time. I keep my ironing board a walk away from either station so I am forced to move. We do what we hve to in order to keep doing what we enjoy.
As for the quilting, I think an all,over design would not work for a hand appliqué top. I do a lot of wool appliqué work and would not want the quilting design to go over the wool pieces. And I think it would detract from a regular applied quilt. But depending on the design and how close the quilting is done, an all over design would work well on most pieced quilts.
This is course just my opinion and I am certainly no expert. If it means the quilting gets finished, then sending it to a LA works for me.