I use Nginx Proxy Manager and whitelist my remote users. They all have static IPs though, so its a workable solution for me.

Before I used a whitelist I would go through the access logs, and could never find any attempts to exploit the endpoints - only some random bots trying to find some admin page assuming it was another service. Not saying you shouldn't take it seriously, but you are likely not subject to these attacks the moment you expose it.

That said, there is a discussion about these endpoints on their repo. At some point they will be fixed (my impression is that they are hampered by legacy Emby code). When they do, you could do this more securely.

Provide them with VPN access. If that's too much for them, then they don't get access. Tough. On the scale of security vs convenience, that's nothing.

If you really really want, you should at least see if you can put a WAF in front, and put the server itself somewhere it doesn't have access to the rest of your network (a DMZ) so that if and when it gets hacked, it doesn't compromise the entire network.

I highly recommend Tailscale, you can share machines/services with unlimited friends on the free tier, and all of the actual auth stuff is handled by someone who isn't me.