i've found with a lot of mushroom species it's not the intensity of the light that really affects them, it's the amount of flow. The more turbulent and strong the flow, the less success you will have...they will eventually detach and try and find a better spot
r. yuma and r. florida IME can handle bright light (anything less than a metal halide tho), and placement higher up.
that said, i tend to keep my shrooms on the sandbed and they do fine while puffing up more than they would higher up.
z