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Apache Guacamole
What is it, and why should you use it?
Apache Guacamole is an client-less server appliance that leverages current remote access protocols on the back end and allows you to just use an Apache based web interface to remotely access your computers or servers. No need to expose RDP to the outside world (which no one should do, EVER), or anything other than one port to allow https traffic.
Benefits
Covers RDP, VNC, SSH protocols, and requires no client software on any machine. Just need to turn on the respective services on the destination device and configure authentication along with a host name/IP.
Risks
Apache Web Server vulnerabilities are your biggest concern if you expose to the outside. As long as that is maintained, there are no other concerns. I would advise using a non-standard port number, MFA authentication, and perhaps even fail2ban to cut down any login risks.
Caveats
macOS and VNC on Guacamole is a little choppy, even over a wire. I an hoping there is a safe port of RDP that could be leveraged safely for use on macOS.
Script Installer: https://github.com/MysticRyuujin/guac-install
GPG Key error when updating Buster-Backports: https://unix.stackexchange.com/questions/75807/no-public-key-available-on-apt-get-update#205732
Useful quick guide: https://jasoncoltrin.com/2017/10/04/setup-guacamole-remote-desktop-gateway-on-ubuntu-with-one-script/
Config Docs: https://guacamole.apache.org/doc/0.9.1/gug/configuring-guacamole.html#user-mapping
Proxy Steps: https://kifarunix.com/configure-guacamole-ssl-tls-with-nginx-reverse-proxy/