We use 8,5 spelenium, typeB, no isues with common ascenders/descenders like petzl bobins (old stop works even better) ascension/basic/croll/turbochest etc.
It stucks too often and too easy, I havent this problems with older croll in the same caves/situations. This croll s wasnt even very dirty. I think it is construction problem, maybe too weak spring if little bit of dirt stucks it.
Yes, You can do it if You use wired connection. I connect handy directly to bobbin carabiner and it is difficult to turn it :D So somerimes i use quickdraw carabiner instead :D
But still I think taht Handy is very good braking binner
I dont like vertaco, for me handy is good option but i also like small carabiner instead. Especially on dirty ropes where handy is "too good".
One complaint about handy - its wire mount.