Well going back into old medical literature you'll find a condition called "penis envy" which seemed to be a fairly common thing with young girls especially those with male siblings basically because they just "want to pee standing up like a boy" which frankly seems like a perfectly reasonable thing. It's definitely not gender disphoria but I wonder if these days it wouldn't be classified as such. From what I've seen of the online trans-masculine stuff a lot of it does seem like it includes a very strong desire to use a urinal including various workarounds for it.