For the life of me I can't find a certain feature-

How do I control the pressure threshold for brushes? For example, in photoshop you set a percentage that will affect how much size variation a brush stroke can have. For example, if my brush size is 20 pixels and I set the threshold to 50%, the brush will never dip below 10px

This is ESPECIALLY important as I'm trying to do clean linework, and can't have too much tapering in my lines. As is, every brush tapers quite dramatically, making consistent line work very difficult.

Thanks

Yes, you can.

Go to the brush settings editor(f5), then to size, and there with the curve widget, make sure that the left most dot is vertically in the middle(and all other dots are above it).

Krita uses a curve based system, where the pressure is read in, then it looks at where it hits on the curve horizontally, and uses the vertical position on the curve to decide the end value. So If you put the leftmost dot at 25% from the bottom, the brush will be at least 25% of it's size regardless of pressure.