I guess you could avoid having to turn it off at the end by turning it off at the part in the sim where you apply a poser. So, for instance, if I was running at 175 frame sim and I put the pose in at frame 75 I'd turn the morph off at either frame 75 or at the last frame. Haven't tried that to see if it works tho, although I don't know why it shouldn't.

Laurie