@Autorotate I wouldn't apply pecards and then get wet. Pecards is pretty much vaseline with some extra oils. So that will repel water. Not totally waterproof, but definitely make it harder to fully absorb. Which brings me to my next point. If you get it wet, make sure it is fully wet and soaked all over. Don't try spot treatment and that kind of thing. Whatever evolution is going to happen, you want it all over to make it look more natural and even.
You probably read some of my posts on TFL. I go by "Toomanyhatsonlyonehead" over there. I've washed many, many leather jackets, put in dryer full blast, etc. I haven't had a "ruin" yet, but I definitely can see ways it could go wrong. The biggest issue with doing with jackets is the zipper. It will cause waves since the zipper doesn't shrink with the leather.
Also, I wouldn't try the wet and dry method with the pale rider unless it's at least a size too big. I don't think this shirt will wear comfortable skin tight. The shirt pocket, placket, etc. adds a lot of thickness, and some of the edges almost feel sharp if that makes sense. I'd be curious to know more about the kind of tanning they did to the leather. It doesn't feel like veg tan to me. It has more CXL type qualities, so maybe it's a combo, or maybe it's veg tan, but there's some sort of top coat, pigment finish, etc. Anyway, I'm really curious to see the journey over the next couple years with lots of wears. I think those wearing on motorcycles are going to speed up that process with the exposure to elements, all that motion, etc. vs someone just wearing around the house like me.