Does it work with custom/bespoke keyboard ? They often don't work in KVMs due to the HID emulation. I notice this Siig device notes to not use the numpad on the

Does it work with custom/bespoke keyboard ? They often don't work in KVMs due to the HID emulation. I notice this Siig device notes to not use the numpad on the keyboard as well, on their homepage, which suggests a compromise.