Fixes and ideas
A single dot
when using a dot material we often get a dot alone at the start of the stroke. You can clearly see it below. It disappears when I release the pen because I added a simplify modifier.
Overlaping Textures transparency
Adding multiple highly transparent stamps on top of each other create color artifacts and black tends to go greenish.
Bonus 1 : input samples as length
Instead of multiplying the number of points between samples, it would be more helpful if the we could specify a length value. This way, we can ensure evenly spaced points regardless of the input speed or zoom level.
Bonus 2 : Stroke transparency
In the dot material, it would be a nice addition that we can set a transparency to the whole stroke in addition to the transparency of each stamp.
That would allow for strokes to layer upon each stroke, doing with a textured material what you can achieve with a Line Material.
Draw order in line material
When I link the strength of a line material to pressure, I notice that when I draw, the strokes are increasingly drawn behind, toward the background. Instead, I would expect the strokes to come toward me and layer on top of the existing strokes, like a real brush would do.
Outline Stroke bug
Using "Outline Stroke" to create a fill from the outline sometimes creates buggy shapes.
Naming : Transparency
Renaming “Strength” to “Transparency” would make it much more understandable for beginners and everybody else I guess. Because that really is what we modify with this slider.