Would be great to have certain attributes that let us place our custom UIs in relation to the UI of TTS.

I see this working like this: you'd add an attribute like TTS-UI-align= "ToolsUI-TopRight". That would set the "origin" of the to the top right of the tools UI (the one that's on the top left of the screen). That way, we could be sure that any Custom UI we build would not overlay with TTS' UI.

Here's suggestions of what attributes you should have:
  • ToolsUI-xxxx: the tools in the top left.
  • MainUI-xxxx: the buttons located at the top of the screen (with Games, Objects, Options, etc)
  • PlayersUI-xxxx: The list of players in the top right corner of the screen
  • NotesUI-xxxx: the Notes box in the lower right of the screen
  • ChatUI-xxxx: The chat box in the lower left of the screen.
*xxxx corresponds to any of the following: UpperLeft, UpperCenter, UpperRight, MiddleLeft, MiddleCenter, MiddleRight, LowerLeft, LowerCenter, LowerRight

Ideally, TTS UIs that change size (PlayersUI depending on player count, ToolsUI depending on host/promoted, ChatUI depending on user's chat size preference) would change the position of that UI locally (and dynamically) for each player.