The way it automatically connects to your home and presents to your devices as part of your home WiFi. So you bring that device with you and everything else works like you're back home.
I use OPNSense and OpenWRT myself and there's no way you can make travel routers this convenient with them.
Although it does sound really nice from a user experience perspective I'm really hesitant with carrying a device with me that without any (additional) authentication would gain access to my home network wherever you plug it in. Would hate losing it or have it be taken from me.
Why do you think this would be difficult to do using openwrt? Wouldn't you just set up the travel router to have the same ssid and password as your home network and configure a wireguard tunnel from the travel router to your home network (that is if you want to be in your home network)
> presents to your devices as part of your home WiFi
That will be fun for browser geolocation based on WiFi name.
It probably needs a panic/border mode to disable all home access in the event of an emergency. You don't want to be crossing borders and give customs officials full access to your home network.
Tailscale running in subnet router mode on a GL.iNet router comes close. You can setup Tailscale through the GL.iNet GUI but to have it also route traffic for everything over to your Tailnet you need to flip one setting via an ssh command.
Not as convenient as this travel router sounds though, but comes close-ish for techies. (wish it didn't require that tweak via SSH. Maybe it'll be added)