I think everything coming out now is (essentially) coming down to the same core chips -- an HDMI-to-USB capture device + WCH's various UART-to-HID products being hubbed together. Just pick your SoC and software to run the show on top.
There's also the class of devices that includes PiKVM, where it's HDMI-to-MIPI for the video capture, and everything else is standard Raspberry Pi capabilities (Ethernet, WiFi, USB host and device, GPIO for motherboard power/reset/LED).
https://www.wch-ic.com/products/CH9329.html