I'm looking at getting a Kanger Genitank and a mini PT3 clone for my wife and I was reading that while you can't use PT3 coil heads in a PT 1&2 you can use PT 1&2 coils in a PT 3 you just have to and a second silicon cap to seal the tank, is that correct cause if so saving a few bucks by getting PT 1&2 coils and maybe getting her a genuine mini PT2 and use same coils for both