uisz is the current "Interface Size" (from the video options menu). It was added so that overlay programs like GW2TacO can properly scale to the client's UI components.
I would submit a PR but I don't know what the possible values are, or what they even mean.
The mumble.md doc does not mention the
uisz
identity field.From @Eearslya:
I would submit a PR but I don't know what the possible values are, or what they even mean.