Hi Dreamer77,
Personal experience always “trumps” any theory and if your mattress is working well for you then I certainly wouldn’t argue with success and there may be no reason to do anything except sleep on your mattress as it is … at least in terms of the latex layers 
This would be up to your “best judgement” and perhaps on whether you would be able to resew the cover (or have it done for you). In the worst case you could replace it and there are some good sources for zip covers (and toppers) in the component post here.
It sounds like you are very close and I would agree that things are certainly looking a lot better better than when you posted less than two weeks ago
Phoenix