If you come up with a way to keep a java fern small without just getting a small variety you will be a hero to many.
What I mean is, no, it doesn't take to the bonsi treatment. It will just keep growing leaves that are tall. When you get enough of it growing it will look bushy, but when you have a single rhisome it will just keep getting longer while the leaves get taller, eventually tiny plantlettes form on the ends of the leaveswhich will give you new plants to use to make the fern look bushy.
Aquascape? I'm a crypt farmer.
It's a fine line between fishing and standing on the shore looking like an idiot.
That IS an aquascape, it's titled "The Vacant Lot".