I've rewaxed a few cheeses after 'needing' to sample or check, and dont think it's a problem. People who use vacuum sealers open and re-seal their cheeses, so why not waxers? Like Alex, I would tend to want to rewax the entire thing, but if the seal seems good on the edges, perhaps that's not necessary. Just keep watch for possible contamination.
For me, in the beginning of cheese making, I tended to wax as the recipes suggested (after a couple days of drying) and that has proven to be too soon. Now, as others here have suggested, after a couple days of drying at room temp, I'll move them into the cheese cave and continue drying for another couple weeks or longer before waxing. Sometimes however, I will want to taste and have found when I do, cracks will develop on the cut surface. My solution for that now is to just dip the cut surface into hot cheese wax so only that one surface is sealed and drying/aging can continue.
The photo is of a recently made butter cheese/butterkrase from 200 easy cheeses that has been sampled twice already
, and each cut side sealed in wax.
It may be difficult to see, but most of the cheese is unwaxed.