I shower before shaving, and face lather 99% of the time. I can actually detect the change in my beard as I shower, as the whiskers break down a bit and plump up with water. So, by the time I've lathered, the whiskers are full of as much water as they can handle, so I don't wait at all, as I don't think the lather is going to really affect the whisker at this point.
This absorption of water is probably the whole point of prep, as the hair is both a bit softer and the extra water makes it physically bigger, and causes it to stand proud ready for cutting.
I always assume that this is why my shave gets just a tiny bit better a half hour or so afterwards as the hair loses that extra water and becomes less prominent.
Here's a very interesting post I found: Water Penetration in Keratin: Revisiting the Scientific Data on Shaving
This absorption of water is probably the whole point of prep, as the hair is both a bit softer and the extra water makes it physically bigger, and causes it to stand proud ready for cutting.
I always assume that this is why my shave gets just a tiny bit better a half hour or so afterwards as the hair loses that extra water and becomes less prominent.
Here's a very interesting post I found: Water Penetration in Keratin: Revisiting the Scientific Data on Shaving