There's a project that did that but for a different purpose - a network KVM using a Pi4 - https://mtlynch.io/tinypilot/
It had to use the one USB-C connector that's used for power for emulating the keyboard and mouse since that's the only one that supported USB-OTG. So you kind of either need PoE or another adapter to both power the device and be able to hae the Pi act as an input device.
It had to use the one USB-C connector that's used for power for emulating the keyboard and mouse since that's the only one that supported USB-OTG. So you kind of either need PoE or another adapter to both power the device and be able to hae the Pi act as an input device.