A while ago I took a piece of white fixed photo paper and ripped it in such a way so that I got a piece of the emulsion to separate from the paper base. I would advise everybody to try this.
You will see that the emulsion (containing no silver) is milky looking. When you wet the piece of emulsion it will become clear as glass. As far as I am concerned this is where the problem lies. Not in the fact that the paper expands and lets through more light and so on. If I remember correctly it was apiece of Ilford MG IV paper. I measured the density of the dry emulsion and I came to the conclusion that it darkens the paper by about 4%. However it darkens the lights and lightens the blacks since it reflects light from the blacks of the print before it reaches the silver.
What I do is print slightly lighter for the lights because of dry-down and increase the contrast just a little bit to blacken the blacks. In effect dry-down is actually contrast down when the print dries.
Anyway one should always dry the test prints. This works for me.