I just found out that you can in fact use SVG brush tips, which is awsome! So I was thinking though, with raster brush tips, you get either a very smooth ‘stamp’ when you set the brush to be a large size (much larger than the brush tip image). If you use a small brush size compared to the brush tip image, the stamp is sharp.
It’s the same principle with upscaling and downscaling an image really, with upscaling it becomes smooth and more blurry, whereas downscaling makes it sharper. Now for SVG brush tips, seeing as they are perfectly sharp (they are vectors after all) it would make sense to have a brush tip parameter that you could use to have the brush tip always scale up by a certain factor to reach the desired brush tip size.
So for example: I have a brush tip size specified at 500px and want a smoothness factor of 2, then the SVG tip would be rasterised at 250px and upscaled to be 500px. If I change the size to 1000px, it would be upscaled from 500px, etc. There is no need to control sharpness, a value of 1 is perfectly sharp after all.
This would be useful to create consistent brushes irrespective of the canvas resolution and the brush size that has to be used to adjust to it.