The embed code is a bit of a blunt instrument. Like much with discourse, it works best out of the box for new sites and new content. Existing sites migrating to it need some extra planning and care… sometimes more than you realize because you’re dealing with a bunch of data and not all features are well documented or behave according to your assumptions from other software.
I think your idea is a good one but it does not exist now, and it may be more complex than you realize… and probably not worth the effort. If you wanted to implement this, you’d have to account for the fact that it would create the topic first and then the user would have to leave the site to go to the forum and reply to it, probably having to create an account first. By then the topic will be created the user may abandon the effort and not even do all that, and you then have an orphaned topic with no reply.
Much easier to mute the documentation category for all users, and maybe exclude the category from latest so it doesn’t overwhelm.
I read the feedback topic on your forum which has some good stuff in it.