I must admit, I am nervous to use non-potted pickups in my doubleneck build, but Thro-Bak tells me they have methods to make their pickups "squeal resistant" that do not require encasing them in a solid block of wax, and thusly, improving the natural tones of the pickup...
The issue is when the windings start to vibrate. That generates the microphonics. Older mini-humbuckers, as are in my '74 SG, tend to be a little susceptible to the problem.
Anyway, there's nothing special about the wax. Keeping a nice, tight winding and keeping the windings from loosening is the critical part. The wax potting is done to hold the windings secure from vibration. If Thro-Bak has another solution for that, I think that's cool. But, I'd want to know how well that solution works under the conditions you intend to play.