You can never wax too often. Yes it can get excessive but you can never hurt it with too much wax.
My skiff stays in my garage and gets waxed entirely after about every 3-5 times out (2 weeksish), and I wax everything...
Steering wheel, guages , cleats, nonskid, hull sides, under sides of hatches, motor, etc.
It may be a bit excessive but it makes for an easy cleanup and im ALWAYS the cleanest boat at the sandbar, or anywhere else for that matter. My friends joke and say Its so sterile I could perform a heart surgery on it.
But unlike a lot of ocd people when im fishing I dont care if it gets dirty with blood slime cast net debris..
If were on the fish I can hose it out later with the washdown...