I've since heard from so, so many people that they aren't getting any bites with traditional job applications, so I've paused active development on it.
My motivations were very similar to yours. I have the personal opinion that there is so much more that we have in our heads that we don't put in our resume/CV and that's the approach I took. You need to come in with a sort of AI biography/career highlight reel on yourself to get the best results. I provided users a template to start from. Yes, your resume is a source of the bio, but there is so much more that job hunters should be drawing from.
That AI biography was the result of another project I was working on.
How do you link the cover letter/resume to a job? Does the user need to come in with a job description in mind? (I didn't try your tool out yet!)