What if Ryouga's special power is to cross dimensions/stories when he's
lost. I've seen enough fics that joke about it. How about a fic that
follows the wanderings of the eternal lost boy.

This is actually close to an idea of mine I threw at Eric Jones as an idea
for one of his faux commercials in Mikado Ichiban.  My suggestion, tho' was
to base it off Sliders, with Ryouga, Nabiki, Kuno and Mikado going trapsing
around the anime universes, trying to get home.  It takes the driving point
of your idea, and adds some more conflict between the travellers.  Just a
thought.