Mad idea for Layered tools or Morphing tools

Here is an idea for layered brushes using the pressure data from a tablet.

In the following example, at high pressure, the tool changes from oil brush to palette knife. This might sound odd but I think it could be very intuitive and offer some creative tools. If ArtRage offered scraping tools for instance, at very high pressures the oil brush could start scraping the paint as if you were scratching at the canvas with the ferrule.

Example shown in code comment to keep everything aligned.

Code:
Pressure  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 100%
Tool A    <------------------------------> Tool B

Example B 

Oil brush ----------------------
                                ---------- Palette knife
Example B 

Oil brush ----------------------
                                ---------- Scraper