ScopeLink works with any hardware input that ships with a Mac driver. This includes PCI, Thunderbolt, and USB-3 input devices from all of the major vendors (Blackmagic Devices, AJA, etc) as well as "Universal Video Class" (UVC) devices like those from Epiphan, AJA and others.
While some Macs have HDMI ports built in, those ports are output-only. You can't use them to input a signal into your Mac.
If you'd like to talk through your specific situation, feel free to reach out to support.