It is really powerful per watt, and has a built-in UPS. Any homelab type things you could do with that? macOS+homebrew will give you a nice *NIX feel, very familiar if you’re a Linux user.
I’m a fan of having a remote homelab computer+disk for off-site storage. This would be a good candidate in that it wouldn’t use excessive power at a friend/family’s place, but may be overkill (I use a pi3 for that).
Can you explain the Ethernet requirement more? Was that just that the computer didn’t have WiFi, or was it set up such that only the wired interface worked with their VPN, or…?
Can you explain your travel router situation? Did you use the travel router to access WiFi and provide an Ethernet port for the computer (I think this is called “WISP mode”)? Or was this an 4G/5G router?
In any event, at least on Android you can connect to WiFi and tether to a computer over USB. It’s very useful for setting up a computer without WiFi drivers, as Linux will almost always recognize the shared Internet (so, it’s functionally a USB wifi dongle with very good driver support).