Pasting a whole catalog into an AI assistant and asking for fifteen RSA headlines looks productive, but I doubt it beats an hour with the search terms report. The model tends to spit out plausible, generic lines that could belong to any company in the category. Then Google rotates them, and the reporting won't tell you which headline actually earned the click, so you learn very little.
I'd give the assistant a narrower job instead. Pull the phrasing customers really use from search terms, reviews and support emails, then have it draft headlines from that language. Keep pinning off until you have enough clicks to judge. Where do you draw the line between AI drafts and copy you write yourself?