I know there are some makers putting out Yaqui slides in Kydex. Don't know who they are offhand, but I know Glock has a leaning toward them. Had one once - had to cut it off my Glock. Dropped it in like it was greased. Couldn't get the d*** thing out of that holster to save my soul.
Truth be told though, the Yaqui slide has serious retention issues when used for the gun it was designed for. To try and use it for other models is looking to have a firearm pop out at a most inconvenient time. Simply sitting down can have a poorly fitted Yaqui slide giving up its gun.
Moisture should not be a problem for a Yaqui slide. There will be your britches, a belt, a belt slot and a layer of holster between you and the gun. If you get wet enough to soak through that you're gonna need water wings anyway.
Besides, Yaqui slides are cheap enough. If I favored that kind of rig I'd order another off-the-shelf holster the day I brought a new pistol home every time.
Not like you're talking Milt Sparks at $100 a pop minimum and a six-month wait time...