UV and plastics do no mix...
Don't know what it would do to your wax (probably not much) and if your base is predominantly black it probably doesn't matter as much since they use charcoal to create the black color (and that gives some resistance), but still, why?
UV causes ageing, embrittlement, cracking, and yellowing in most plastics including epoxy and urethanes (boots) and especially PEs (base). We usually test plastics by sticking them on the roof and letting the sun bake them. Now you probably won't see any degradation after a couple of hours but it's just not a great idea. Build a hot box! More consistent and no UV.