There are a few, like this add-on for PiKVM[1], a fully integrated version from Geekworm[2], and an as-yet unreleased 4-port IP KVM switcher from GL-iNet[3].
reply[1] https://technotim.com/posts/pikvm-at-scale/
It also looks like BliKVM is now making the BLiSwitch: https://blikvm.com/docs/device-guides/BliSwitch-v2-guide/
replyPiKVM themselves offer a 4-port switch, which can be chained five times, giving 20 ports in total: <https://docs.pikvm.org/switch/>
reply