This could go back an forth all day but I will say that your dismissal of my last source seems flippant. They are studying the behavior of the fish, putting them in an environment that would unduly stress them would defeat the purpose of the experiment. By saying that "I'm not sure animal testing labs have the best track record when it comes to animal welfare" your completely avoiding the point with an inflammatory statement. I did not site an animal testing lab at all, rather a scientific study done by a major educational institution.
An animal testing lab that is part of the University of Michigan is still an animal testing lab. I believe animal testing is a necessary evil but its not an excuse to treat pets the same way : /
Finally the assumption that that these are "bad practices" simply because they deviate from your own shows a clear bias.
I believe that keeping an animal in conditions that don't allow it to exhibit natural behavioral patterns is bad practice. Since you appear to enjoy a scientific approach maybe the only way to find out for certain is to move your fish to a larger tank and do plenty of personal observation. There is no substitute for personal observation and experimentation IMO and I promise once you see the difference you would never even think about returning him to a bowl.