If you do that...I would paint the board with silicone...don't want any possible bottle leaks to fry your board. Provape paints silicone on all of their boards, in case something goes wrong. Were you planning to dremel out a squonk hole? You could also cut a rectangular piece of wood or metal and cover the board area...maybe attached with some mini brackets? but then you would need a really thin bottle.
There doesn't look like a ton of room in the circuitry area...I wonder if you could just build a new front that would make it deeper and make a half cover for the battery compartment, so they don't rattle or unseat...LOL, sorry the engineer in me is having a field day....