Custom Terrain Editor UI

Hello Unity Fellows,

I am trying to write a custom Scene GUI for the Unity Terrain Editor as I'm not a big fan of the whole dropdown menu thing. So I actually wanted to start simply by selecting Paint Tools via scene view buttons.

As far as I can tell TerrainToolShortcutContext.SelectPaintTool<>() is the only(?) function to do this but it doesn't work as all the basic terrain tool classes like SetHeightTool are protected (and I also don't really understand how to set ShortcutArguments by code)

I also tried to circumvent the system by just triggering the shortcuts directly but it looks like I can neither trigger shortcut commands by code (or can I?) nor can I simulate key presses.

So, what would be the correct way to approach this?

Thank you for your time.