These two 18 hole par 2 kitschy courses are definitely courses, but they could only be used for either just messing around or practicing different kinds of shots.
Tiki Course
Flying Armadillo Gold Course
You can't have a round of disc golf without a course. Not even a practice round. IMO a practice area is random basket(s) that you make up shots to practice on. Wether putting, approaching, or driving doesn't matter. Whereas if it has a designed layout, it is a course, no matter the number of holes.
I understand that the earlier examples are likely only ever used for practicing, but they follow a designed layout with a designed par in mind to compare against. So it is a course that you practice on. Much like the Tiki course at the Blockhouse complex or the one at the Flying Armadillo complex.
But that's just my two cents. Certainly having something like my idea is a much more definitive line in the ground as to what constitutes a course and a practice area when adding courses to this site. Whereas if we are going fully on how good, hard, realistic it is to have a league round at a course, that line is going to be murky at best.