Re-treating traps in mid season is one reason to wax but frankly that's not a big issue with me as I have accumulated a pile of traps over the years, and rarely run out. It can, however be a factor if you have only a small number of traps.
I like the idea of being able to readily strip the trap down to bare metal -- any time. One thing to consider is build up. This is not a huge problem but coat after, after coat, after coat of dip, and it starts to build up on the trap. Every time
I boil off a waxed trap I am back to square one. There is no build up with wax.
Now I've mentioned this before, but you can wax over dip. If you want to retreat a dipped trap in the middle of the season, boil it off and wax it. At the end of the season, boil it again and you're back down to the dip layer. Then you can redip the trap, if you like. (Be advised that dipped traps will stain your wax, but I don't consider that to be a problem.)
Here's on final thing I should mention. I do not trust any method for cleaning land traps other that boiling. I do not believe you can get traps thoroughly clean and odor free simply by washing then at a car wash or whatever. There are too many cracks pours and crevices. Iím always going to boil traps to clean them. If I'm bound to boil the traps, and boiling can and will strip away all
the old coating then wax fits the bill nicely.
But I must reiterate -- I don't see anything inherently wrong with dipping land traps. I don't do it, but there are a lot of successful trappers that do, Put it this way, I don't think anyone having a lack of success in catching canines can blame it on dipped traps.