Pi-gadget vs pi3-gadget, cm3-gadget, pi2-gadget

Is it the case that pi-gadget unifies pi3-gadget, cm3-gadget, and pi2-gadget, and that going forward, should we use pi-gadget, and not the others?

Matt

My understanding is that you use the different gadgets for UC16, but use the unified gadgets for UC18 (and probably eventually UC20 as well)