I had a similar solution but got tired of swapping the cable b/w the two laptops. I found https://sabrent.com/products/sb-tb4k which keeps both machines connected and can switch b/w the two with a "switch button" which is connected to the KVM switch.

This was the only KVM I found which connects to 2 Thunderbolt devices at once, everything else was relying on HDMI+USB3 for the host connection.