Melding HQ Vanya - BLM Materias

Hey you guys.
So im melding my full HQ set (;)), what stat's i need the most?
I bought x4 +7 INT materias (89k each) just to realize i can't meld them in - i don't get it. Is there a stat cap or something?
If i can't meld more INT, what should i get next?
From my understanding casters need 427 Acc for Coil, is that correct ? Please help!

Already answered you on the other thread. Yes crafted HQ is already caped for main stat, just use what I wrote you in the other thread from Crit to the last one.