Square looking is deceiving
as are many " proven aerodynamic facts"
Once you start measuring things - surprises are the rule- not the exception.
How fast are really slow flying models actually traveling.?
When we were doing design work on slow indoor aerobatic stuff- we found that getting a cruise speed of under 4 yards (meters) per second, was far more difficult than it seemed.
Many indoor models will not even get close to this
The ONLY one we found which did it reliably?
The VAPOR.
None of the superlight Bind n Fly acrobatic models even came close
When we duplicated the wing loading of the VAPOR on a 30 gram model- (The Vapor weighs 17 grams) we came close
The Vapor had more chord and an extremely low aspect ratio.