> Actually one of the tools that you could use to admin your mum & dad computer

I do exactly this! I keep Tailscale running my family's shared iMac, making it easy for me to remotely connect to it and screen share if necessary to help. I went a more complicated route[0] and installed Tailscale as a system background daemon that runs as root and starts up before the first user login. Which also means no GUI interface, so more protected from user error.

[0] https://github.com/tailscale/tailscale/wiki/Tailscaled-on-ma... (the standalone variant is also entirely opensource, unlike their macOS GUI app)