I’ve never had the time to figure out the brush engine in Photoshop until now, and after messing around for a while I’ve decided I’m ok with it. I do still prefer Krita for this kind of thing, but now I can at least modify photoshop brushes in ways relating to pen pressure, and change the brush angle. If you want to mess around with brushes yourself, you can find the settings in the brush window (Window>Brush). If you browse through the sidebar, various aspects of the brush can be set to respond to pen pressure by clicking on the “Control” drop down menu below the feature you want, and selecting “Pen Pressure”. Provided you have the right kind of tablet, you can now do all sorts of wacky stuff. Even if you don’t have a tablet which responds to pen pressure, there are still a lot of fun settings in the brush window. I suggest just messing around with them for a while and seeing what they do!
This might call for a video of you using the pen–what do you think? It could be cool to have two cameras, one that shows you drawing, and one that is simultaneously recording on the screen the drawing, as you talk about pressing down and letting up and what happens when you do so.
Love your writing style and your illustration!