I have been playing around with a couple of theories / ideas dealing with this melee class assist issue using KA.
What I have come up with is this:
If you have them set to return to camp
ReturnToCamp=1
ChaseAssist=0
they will return to camp after each kill. I figure this is how the rotine is written and must process in order to complete and reprocess.
Even The MA / Tank would return and reset at camp if all the mobs on Xtarget were mezzed / not fighting.
If you have them set to follow your MA,
ReturnToCamp=0
ChaseAssist=1
They don't reset to camp BUT
If your Tank is also your Puller (pullertank), then they are chasing him around wherever he goes (getting stuck, drawing agro, and looking like a total bot.
If their MA stays in camp (non-melee type) they WILL return to following their MA before engaging the next mob.
Best result for speed on engaging the next mob came from them not being set to do either.
ReturnToCamp=0
ChaseAssist=0
They go from one combat to the next without an extra move inbetween.
However, if for some reason (summoned, chasing battle, push, knockback) they get to far away, they have no script on how to get back to the group.
I am currently trying to write a downshit for my Mage that will check a group members distance and if to far away to CoH them.