Go from 3 to 5 standard pre-set pen weights. I find the jumps between the 3 weights you offer too big and my perfect weight would be between your thinnest and middle one. I suggest to mimic the 5 pen weights Apple offers in the IOS Notes pen integration.
The fact that you can define the 3 sizes with the slide is not enough for you?
On my side, it's not about the 3 sizes...
Its more that I need to modify the slider all the time... so in a way, you are right - I would even say : favourites should be a combination of colour AND thickness