I also recall you can spin a 140, so semi aerobatic.
There is a big difference between being able to spin an aircraft and it being Semi aerobatic
Really there is no such thing, it is either Aero or not, but generally aircraft that have no inverted system and low "G" limits (+6, -3) are considered semi aerobatic.
140 normally only has 2 seats, if it has 4 then it is really is hard to use all 4 with any sort of bags and fuel load. Many only had a handbrake - not that hard once you get used to it.