I'm thinking ... add a button like: [Is my site AI-Searchable?]
When they click it, it asks, "What's your home-page domain name?" --> [__home_domain__]
Look for the existence of "<home_domain>/LLMs.txt"
FOUND: say, "Congratulations! Your site is AI-Searchable, but be sure you update it regularly"
NOT FOUND: say, "Sorry, not yet. CLICK HERE if you'd like to see what that would involve"
The challenge is if they've forwarded their domain to some SaaS platform, then the results might not be valid.