Bl_context_mode for active tools in texture painting

I’m trying to add an active tool to texture painting mode.
The bl_context_mode property doesn’t work with “PAINT_TEXTURE” though.
Everything works as expected with “OBJECT” or “EDIT_MESH”, but not for texture painting.

What is the correct value this needs to be set to?

I reported this as a bug as the error seems like there’s something wrong with blender:
When a wrong key is entered the error type is a KeyError, but with “PAINT_TEXTURE” it’s a NameError.