I don't get much appetite stimulation from it. If you do, yeah, limiting the dose would be advisable, but I'd start at the normal 4-5 pumps and adjust from there.
I recommend limiting transdermal products to one product at a time.
Unless you have the time to apply them on different sites, and hours apart.
Skin is limited on how much it'll be absorbed before being saturated.
"If you want to impress me, build a 20-inch arm with a 20-pound dumbbell."~Dan Duchaine
SNS REP, Precision Nutrition Lvl 1, NSCA CPT
And I've used multiple TDs simultaneously; as long as the application sites are different, you'll be fine. I've gone so far as to do Eviscerate on gut and obliques, derma on chest/shoulders/arms and trenazone on neck/behind ears. Funnest cycle I ever ran.