Most remote software pushes the picture through the cloud of whoever built it. Here your two machines shake hands and send straight to each other. The meeting point in between only moves bytes, and it has no key to open them.
A sleeping computer drops its connection. Wake-on-LAN can't cross your ISP's router. Most remote software stops there. Your computer schedules its own wake-ups in hardware. Every few minutes it checks for a caller, then sleeps again after eight seconds if there isn't one. Call while it's asleep and you wait in a queue that tells you when it comes back.
The other tools all ship a vendor console. Whoever takes over that account reaches your computer. MXa has no such door. No account, no email, no password to lose.
The shared box at the office is somewhere you can't install software. Open Chrome or Safari, go to the remote page, type the ID and the code, and your computer's screen is there. Same end-to-end encryption. Close the tab and nothing stays behind.
The relay joins the two ends and copies bytes. Session keys come from the 6-digit code plus a per-session ECDH secret, and the relay holds no part of that secret. What passes through it is a stream of random bytes.
Both ends sign a fresh random challenge and compare the proofs. The code itself never crosses the network. Record the whole session and pick it apart, the code still isn't in there.
The app tries a direct connection for about 300 ms before falling back. At home or in the office the two machines talk to each other, and no server sees the video. You never pick a route.
The comparison reflects how commercial remote-control software commonly works. Individual products differ in the details.
Install the app on the host at home and give it a role. At the other end, type the two numbers, from the app or from a browser. Nothing to disclose about yourself.
