It's cool Sparkle is still around and offering an alternative for app updates. I remember working with it in Quinn on Mac OS X like 10 or 15 years ago.
A better solution in most cases would be to integrate some kind of "update available" affordance into the window chrome, as many interfaces now do. And (with user consent) most apps should simply update themselves when they are not in active use. That is (again, with user consent), desktop apps should simply behave like SaaS apps.
At least for me, you've certain done it better than almost any other updater.
God, I still miss Quinn. For years after its official demise I still had a copy, which I kept playing, until the 32bitocalypse made that impossible.