Standing upright, no, my CC weapons don't print. But when I bend over, it's pretty hard not to miss the muzzle printing in the back, or when I twist at the waist, it's common that the grip heel will print on the back of your shirt. It's just a simple fact, spandex or not.
Then consider that my wife, sister, mother, mother in law, and sister in law (among other women in my life) all have their CCW licenses, and when it's hot and they're "steppin out in their tight fittin jeans", it's not very hard to spot their weapons.
I do actually like IWB holsters, but I haven't been very happy with most of the available options out there.
From an "engineering" standpoint, having a "filled" pancake IWB would help prevent the grip heel from twisting away from the body, as well as improve comfort against the body, and prevent printing in general.
I'm mostly looking for something that would be more comfortable, like a crossbreed Super Tuck, but more compact like a DeSantis Soft tuck.