FYI, for reference, noticed fairecasoimeme from ZiGate is working on PR for ZiGate discovery support:
https://github.com/home-assistant/core/pull/68577
PR will add ZHA automatic ZeroConf/MDNS discovery of ZiGate Ethernet Gateway (not WiFi Gateway).
PS: Other Home Assistant / ZHA developers started assisting fairecasoimeme once PR was submitted.