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 google or apple.

Just buy the lifetime Plex pass before the price goes up then.

If you have Plex pass you dont have to worry about it. Others can still remote play from your server free. Actually more so because the mobile app is free for them too now.

You convinced me I need to appreciate tailscale somehow even more than I do.

services.tailscale.enable = true;

If its just a simple static page. Just use cloudflare pages. It scales to zero and would probably be completely free for your use case.

Vercel is even easier to setup but they don’t allow businesses on the free tier so it would be $20 a month for pro plan.