I think it's practical for anybody crazy enough to want to try to grow fish quickly for aquacultural needs.
The problem is to figure out what you've just selected for. If your fish are loving a particular feed, are you selecting for the taste of the feed, or the shape, or the buoyancy....or maybe consistency. It's all so complicated and intertwined. When my bluegill grow quickly in indoor tanks am I selecting for food conversion?...or maybe ability to thrive in salinity??...or maybe preference for a round tank????. I think you get my picture. Any time you try to select a fish, or other animal, there's a myriad of things you may be selecting for and not realize it. It's virtually impossible to isolate and control all your variables. I deeply respect scientists who do this sort of a thing for a living.
