People will provide feedback on irrelevant places

Blog posts, twitter posts, stackoverflow... "Please post your bugs in our tracker", "please ask on our mailing lists " will not help. Just accept that.

If your project reaches some level of success, you may also learn that some people will hold on to feedback, criticism or even known flaws so that they rather can write a clever paper about it down the line, or perhaps make a presentation about it on a security conference.