Ours grew along a creek far from the house so I don’t know about the flies. I have heard of making jelly of them but the sliminess factor is very off putting. They also are more seed than fruit.
The ones I had were soft but not slimy. I ate mine while they were still green on the outside, though. The seeds were large but there was still as much fruit as you would get from an apple, because the pawpaws are larger than apples, 5 to 6 inches in length, as big as an average russet baking potato. The seeds were less than half of the total fruit, sometimes only a third. I still prefer the flavor of big bottomless wild persimmons to pawpaw, but pawpaw would probably be pretty good as a frozen treat.