Its a lot simpler then that. Dont add them to your tailscale account. Each user should have there own tailscale account. Then you just send them a link to share your machine (your server) with their tailnet. Then all of there devices they have added on their account can access your server.

Bonus: send them referrals and you get your device limit increased when they make a account. Which all they have to do is sign in with their google or apple account.

This is the way.

Unexpected good elon take. Patents and copyright laws have probably held us back at least 50 years worth in advancements. So much R&D is just solving problems that have already been solved.