If it's just the 'skirt' of the mask (the bit that makes contact with your face and forms the seal) that's sitting on the edges of the hood then you don't have to trim your hood. I don't like hacking away at new kit with sharp edged objects
I've just got in the habit of running my finger around the edge of my hood and flipping the edge over the mask skirt. It's not that uncommon a practice.
You do, of course, have to practice mask removal/refitting with the hood in place to get into the habit of doing it in all situations...
Best of luck with the OW Anita - let us know how it goes
[Edit] I should point out (before it's done for me!) that this does add extra task loading should your mask become dislodged, but if practiced enough it should become automatic. I've done all my mask removal/replacement skills with a hood on and I practice it regularly in both pool and open water...