I got a new 4k 144 hz monitor (Alienware aw2725qf), and managed to get it working through a kvm at full speed with my old primary monitor, a 4k 60hz lg. also using keychron q3 max, audio engine a2, mx master 3 through the kvm. I am honestly amazed everything works because I spent 35 dollars on it.
the kvm is hooked up to my m1 MacBook Pro (1 monitor runs through my owc thunderbolt 3 dock, and the main monitor has a separate cable coming from the KVM as tb3 does not support 4k 144hz) and my gaming rig (5700x, rtx 3070)
I also added a charging dock from my AirPods Max and an Anker wireless charger for my phone. I don't think there is anything else I could ever need in my setup. Let me know your thoughts