I've left the 7-9-10 a couple of times, but never the 7-8-10.
First time I ever saw someone leave the 7-9-10, I saw it picked up. In fact, other than myself (I've never made it), I've seen the 7-9-10 converted three or four times. But I've never seen anyone pick up either the 7-9 by itself or the 8-10.
Jess