I was wondering, if there is a reason, that britain has lots of areas with high propability and the mainland has not, but then I saw that the growth records [7] indeed only cover the british islands. So I suppose the data on the map is not really accurate as of now?

Otherwise what I would have expect from such a site, would be of course also detailed informations on how the mushrooms look exactly and where to look for them specifically. (And also a warning, that if you pick the wrong ones, you die a horrible death and even if you pick the right one, but are in the wrong mentally conditions, your are into horror either)

Anyway, your project is nice and your map inspired me to have a look in my area and see, if it matches your data.