When connecting multiple HDMI displays they will all the same name from qtbase/src/platformsupport/kmsconvenience/qkmsdevice.cpp
You get "HDMI11" for every display that is connected to hdmia port.
Problem then comes when you try to map input devices to these where the json format only allows to map them by name. For example if we have 3 displays and 2 touch panels without unique naming you can't assign them to correct displays.
Connector name should have a running id or something that makes it unique e.g. field connector_id .