I also trim after each block, but I do my blocks in sets, so it's normally sew up a group and trim, them move on to the next.
I'm finding I do better if I get up and do a bit of standing a little more often. In the end, I can sew a lot longer in total if I'm not sitting for so long in one stretch. Usually I'm out of my chair at least every 15 mn except when binding a quilt. And since I have an LA, quilting is 100% standing for me.