Update,
While I was watering late this evening, I noticed that the rubber sugar apple was falling off the tree! with ants invading the top of the fruit at the stem!
I quickly plucked it, and washed it up...then photoed it, and ate it!
It didn't have the texture of the first fruit I ate (a bit early I assume), this one was like a super firm gefner., or similar in texture to some of the canned jackfruit I've had....not near as firm as the first fruit. Maybe that one was a fluke? or if you open and eat them early, they can be even more firm?
seed count was low as well.
Maybe this is your sugar apple, if you don't like the soft texture of all of the others you've had, but enjoy the taste?
here are some pics.
I tried to demonstrate how the pulp could be thin sliced, like swiss cheese! maybe u can tell from the pic?
hope u enjoy.