TSW has a modifier key for this (ctrl by default), so if you have a GTAoE effect bound to 1, and you hit ctrl+1, the effect is automatically centered on a target.
This is NICE. It is really intuitive, and fits well with idioms like the "self-cast key". They are also talking about adding a proper toggle for it.
Either way, this would make GTAoE more fun for me in some pretty common cases.