After trying both out, I'm sticking with <t>, it's mainly cause you can't really see as many debuffs on focus target so I usually target or <mo> allies. Gives me a better visual for dispels etc. With the boss focus targeted, you can still see inc actions. I wish something like

/ac "Cure" <t>
/ac "Cure" <tt>

would work like we wanted it to, but unfortunately it seems buggy :<