I know I am (was) using the level1techs KVM (DP1.4 for 2 x PC’s 1 x Monitor) and it is not compatible with my new Samsung Neo G9 Odyssey @ 240 HZ. I have to downclock to 120hz, and even then, there are a lot of drop outs. This is using the recommended Club3D Display Port 1.4 cables. I also tried with StarTech DP1.4, same behavior.
Drop outs are a signal integrity issue, for sure. And if the signal is imperfect and you introduce compression the compression amplifies any problems on the cable.
In one customer instance, contacting samsung support they sent them a new firmware for the monitor and that resolved all issues, too.
I might try to pick up a G9 odyssey to use it for testing