Mobile apps for non-Plex Pass holders have a one minute limit for playing video.
The limit can be removed by making a one-time $5 USD in-app payment.
The limit can also be removed if you invite him into your Plex Home. However, this has security implications as people in the same Plex Home can use Fast User Switching to change accounts. You will need to PIN protect your account if you add anyone to your Plex Home.
Non-mobile clients have no one minute limit. He could use a Plex TV app, streaming device app (Roku, Android TV device, AppleTV, etc), or Plex Desktop / Plex HTPC on a Windows/Mac/Linux system.
That works perfectly well, actually. Before I went all in on Plex (bought the Plex pass and a DVR) I would watch content using my iPhone’s web browser to stream video to it for free.
With the Plex Pass, I didn’t need to pay to unlock the app for viewing, but I could have just done that one-time for 5 bucks instead.
Or they could check out if there’s a native Plex app for their Smart TV platform.
The 1-minute restriction and app activation only apply to the mobile apps.