Mogas disadvantages
One is that it can kill you.
A friend of mine had an immaculate restored WW2 trainer that he kept on a private strip.
He went to a rally on a nice warm day and there was a bit of a queue to depart so everything was warm, fuel and engine.
Shortly after take-off he lost power over some trees and stalled it in. He was killed, his passenger seriously injured.
The AAIB found he'd got Mogas in the tank. The a/c was not approved for use with Mogas. The conclusion was that he got vapour lock due to warm fuel, a high ambient, and the long wait at the hold raising teh temperature inside the cowling.
Mogas is more volatile than avgas.
Mike