...So long as whatever auto-update mechanism the software has can recognize where your paid support ends. I've had a problem in the past (I'm afraid I no longer

...So long as whatever auto-update mechanism the software has can recognize where your paid support ends. I've had a problem in the past (I'm afraid I no longer recall what the software was offhand) where I paid for something with a model like you describe, but then after my support ended, the auto-updater updated me to a version that I hadn't paid for—and I was dumped back onto "free trial" mode. The auto-updater also needs to not notify me of updates that I can't get without paying. That's just spam at that point. Apart from that, I generally agree that that's a decent model to follow.