As a maintainer, discovering that a PR is AI-generated just absolutely saps any motivation I have to actually review it. I've never been a great reviewer, and AI means I have to watch out for really different kinds of errors. There's also the potential for extra friction with interactions with the "author": some people try to pull a "I'm just a smol bean, not a programmer, how dare you ask me to do anything" in response to changes, while others just play a middleman role in between you and the AI they're using.

If you're actually motivated to get a working fix upstream, and you're willing to do more than be a passive player, then it's not necessarily a problem to submit it (subject to responsible disclosure, of course)... but you also say that you don't have the time to properly engineer it, which makes me think you don't have the time to be sufficiently engaged in the upstreaming process anyways.

AI has inverted the effort - in the past a PR meant someone had to come in, read your ticket, documentation, code and tests to successfully author a PR. Subsequently reviewing that PR would typically take less time than authoring it and you would receive fewer PRs.

Now it is it the opposite, maintainers are flooded with low effort PRs that take more effort to review than author, but the author is unable to see why this is problematic to the maintainer and the project.