Mechanim muscles reset, any way to save?

I'm new to Mechanim. I imported a model that was modeled pretty much in T-Pose. Mechanim said it was not, so I hit Enforce T-Pose. When I go to the Muscles tab, the model is slightly crumpled. When I run it (with IK), the joints are kinda messed up. So back to Muscles, I set the right half up to match the T-Pose, hit Apply, and run my scene, now the right side of the model looks just right. yay. So I go back to Muscles to fix the left side, and it looks like it did NOT remember my changes to the right side! I'm afraid to edit just the left side as it may apply the crumple back to the right side. Do I have to make ALL the edits to muscles in ONE muscle-edit session? Or is there any way to save/load muscle configs? Or will editing just affect the bones I change in that session?