A resounding yes! Raw mushrooms will rot fairly quick so dry them cracker dry, get some mason jars and a few desiccant packs and they will last a long time in a space that is dark and at standard room temperature. The breakdown temperature of psilocybin is actually quite extreme and a dehydrator ain't going to reach those temperatures.

There are actually two (but technically the same) main psychoactive compounds in raw mushrooms: psilocin and psilocybin. When you injest shrooms, our body will break down psilocybin into psilocin which then can pass through the blood-brain barrier and cause a trip. I have read that raw psilocin in the shrooms themselves is more unstable and does not store very well. Psilocybin is much more stable.

Since you intend to use them medicinally, you will need to account for the inconsistency of the psilocybin content. It can vary from mushroom to mushroom and flush to flush quite a bit. So: Dry them all, grind them all into a powder, mix well and then experiment with different dosages with that powdered blend. Once you find a dose that works for you, consider loading up a bunch of gel caps that you can buy off of Amazon.

Oh, almost forgot: Psilocybin tolerance is very real and it develops extremely quick. If you end up tripping off of a dose, you likely will not trip again off the same dose the next day. Doubling up the dose is about the only way to trip again but it is extremely wasteful. (I tried once. I ate 5g dried one day and basically gave up after +10g dried the next day. Sure, I had a mild trip on day two, but like I said, wasteful. I wait a week or two now between trips. I took a short trip to the outer planets last weekend, so I am likely going to pass this weekend.)

If you end up feeling too much of what you want for a medicinal dose, wait a week or so before experimenting again so you can get more of an accurate feel. Once you saturate your 5HT2A receptors, they will absolutely nope-out for a few days. Many sources will say that microdoses do not cause such an extreme tolerance, for whatever reason.

It'll be incredibly difficult to properly dose them if not dry.

Today that full shroom is 10g, tomorrow it's 9.5, the next it's 8.

Once they are dry it'll be more consistent.

Yes. If you are not planning on consuming them fresh, drying them is the best way to go. There are different methods to choose from, but I would avoid any process that uses heat, which can damage the alkaloids. If you don't have a dehydrator, you can get a decent little unit for $40-$50 on Amazon.