If I had it to do over again, I wouldn't cut another hole, but what I did was pull out the two rubber intake tubes from the front of the airbox and cut an additional square hole in the center front of the airbox in between the two existing holes.
I think just pulling out the tubes would give plenty of flow, and you should try it before making permanent mods to see if the intake noise drives you crazy.
I tried an airbox mod on an old Yamaha Vision I once had, but the intake noise was totally obnoxious, so I put it back stock.
It wouldn't be hard for me to just cover the hole I cut with a piece of plastic JB Welded over the hole I cut, but I don't mind the noise. The V-4 intake noise sounds a lot like my exhaust with the slip-ons.
My brother had an old VFR750 with a SuperTrapp exhaust on it, and it was too loud and raspy for my taste. He ended up putting the stock pipes back on. He bought it with the SuperTrapps installed, but the guy gave him the stock exhaust too.
Good luck with the mod! My intake tubes had been siliconed in by a previous owner. I think it had been raced and the tubes had been removed before, but they came off pretty easy.