I have both hooked up to 2 monitors. A shortcut triggers MagicSwitch to switch my keyboard and mouse to the other machine, while it uses BetterDisplay to send a DDC command to the monitors that makes it switch inputs.
Bound the whole thing to a key combo, and now I can easily switch between two machines.
* Using the keyboard's switch-device button moves the keyboard to the other laptop.
* Logitech's Options+ app automatically switches the mouse to the same device in response.
* Claude vibe-coded me a native app that runs on both laptops and sends a DDC command to the monitor to switch inputs any time it detects keyboard and mouse both going away in quick succession: https://github.com/jawj/mxswitch
https://news.ycombinator.com/item?id=49823733
In this case the key thing was to make this work with an old MX Master, which isn’t properly supported for one-button multi-device easy switching.