Try running hot water in the bathroom during your test to see how the finish reacts to steam. Honestly, overnight humidity checks are good, but steam from showers can cause bubbling faster. Ngl, I learned this the hard way with my kids' bathroom cabinet.
Bathrooms are the worst for that. I started leaving test pieces in the actual room overnight to see how they handle the humidity swings. Saves a lot of grief later.
How many times have I ruined a finish by not checking the humidity? @willow_robinson, your overnight test trick is genius. I once painted a cabinet without testing and it bubbled up like bad pizza dough. Now I feel silly for not trying something so simple earlier. This is why I always read your tips.