I would say most have not even tried it. Landing a single kill in a not so uber plane is fairly easy even for a beginner.
Actually, it's pretty hard, even for veterans. That is - if they don't follow around the horde.
All those vets and experts bragging about how they use mid-war planes? Well, in truth, you gotta see
WHERE and
WHAT SITUATION they fly, rather than
WHAT they fly.
The only guy I've really seen with my own two eyes, who flies mid-war planes and still manages to survive wherever and whenever, is Leviathan alone. All the rest is gangbangers, cherry pickers, friend-baiters.
Maybe limiting a planetype, or takeoff times might not be an answer.
How about if there was a way to split people up so they cannot form arbitrary hordes?
If you look at the MA, a good-sized furball never lasts long. The side which takes the upperhand increases in numbers, and the side which takes heavy losses just abandons the field/sector and goes away someplace else. As a result, the side which one a few waves of A2A fights becomes a horde there, and the side which lost a few waves goes someplace else and forms their own horde.
Two gigantic hordes, and yet they don't fight each other - they fight buildings and pathetic number of hopeless defenders.
IMO, resolving the horde is probably much better way to bring back the MA fun, rather than limiting a planetype or takeoff time.