Ualaa, thanks for answer, as always.
Yes it is a game issue not SW, but I think there is a SW way to help us with this.. And since I use ISBoxer...

Something like... main transfer target name "XXX" to ISBoxer & ISBoxer using macro function(/target XXX.. not assist on main) help toons to interact with this NPC.
Unfortunately AFAIK macros thru ISBoxer need /reload command to take effect..

Ok let's wait for some ideas or updates on this topic