Well, I wasn't going to say anything but you were talking about using a tip tool but.......
I've always been told that you should never use one of those porcupine tip tools on LAYERED tips but even so, if I remember correctly some of the people who pay attention to this sort of thing, said that the porcupine tip tool helps to delaminate the tip, not glaze it over. Anyway, school is still out.
Only use the Cuetec "BowTie" texturiser on it that is designed for deglazing etc. did not use the tip pick part or porcupine as you called it. The thing i used is just a scuffer to rough the surface up!