I wonder if there is a way to temporarily activate the smear or the soften tool while you are painting with the brush. The same way we can activate Smooth or mask by pressing Ctrl or Shitf when we are sculpting. Same would go for substract while you paint.
It would just make sense as I think those hotkeys are not used right now while you texture paint.
I wonder if there in any plugging or way to configure the hotkey that does the job.