I had wendtii under high light and in dirt...it was short at first but then with all the growth potential decided to get huge, and kept trying to grow taller than itself.
If you have your crypts growing fast, its worth trimming them back if you don't want them to take over....wendtii can and will get a foot tall if you let it.
My wendtii is now in eco complete, still high tech, in a taller tank, and its not getting the hight it did with a dirt substrate...but if it starts getting too tall I've got my scissors ready.