Has anybody found any popular "wisdom" about holsters or concealment in general to be untrue or not universally true in their experience?
The classic that comes to mind, although I've heard it less often in recent years, is that shorter guns are somehow more comfortable AIWB. I think most of the folks on this forum are up to speed on the benefits of a longer holster for many if not most people. For those who haven't really thought about it, or have a limited frame of reference, I think it's easy to see why it might initially make sense to assume shorter = more comfortable. I've personally found that lengths approaching G34 are ideal for me for most guns, although I can live with less. Still, the industry keeps putting out these weird, shorter barrelled versions of compact pistols- the 3.6" M&P compacts and the Sig P320 XCompact models come to mind. I can't quite wrap my head around what they're chasing with these models when the G19 form factor has been the public's darling for decades now.
One oft-repeated observation that I've found untrue in my experience is that snubby revolvers "just work" AIWB and that holsters for them don't generally need the same concealment features you see on semi-autos. This has usually come from people more experienced than me with them, so I'm sort of torn on whether I'm just a novice who doesn't know anything, or they're just not carrying their snubbies in challenging attire. *My* experience so far is that the profile of a snubby acts basically as an inversion of a holster wedge or pillow- the gun is very narrow up front, and widens at the cylinder which is generally in line with your belt. The wedge shape and pressure make the muzzle want to cant inward, tilting the grip outward. With small enough grips this could still be a non-issue in terms of concealment, but I find it pretty uncomfortable using kydex and it does result in more printing for me. I find a well-placed pillow wedge is effective as a remedy, but that's still adding bulk to the package and bringing the overall footprint more closely in line with the size of a G26 or G19, albeit with a much more concealable grip above the belt.