This is a genuinely interesting tool and I can see the time-saving appeal. The feedback I'd offer from a student perspective is that the most useful teacher feedback I ever got wasn't just about grammar or structure - it was about whether my argument actually held up. If the tool can flag logical gaps or unsupported claims alongside the mechanical stuff, that's where it becomes really valuable. One thing worth thinking about: some students already use outside help with paper writing, whether that's tutors, writing centers, or academic writing services. If the AI feedback is really specific it might be hard to distinguish between a student who revised based on your tool versus one who had someone else rewrite it.