Unfortunately, experience. A good dose of people skills help, but you need to know what makes real money move and get contacts in your area. Find someone who has succeeded in your area, and try to get into those circles.
I tried blender video editor just the other day, and this problem was still there -to the point that I actually went out and found kdenlive the same day!
Takes way too much RAM for my ADHD brain. If I work like that, solid concepts slip out of my grasp and I have to work them out all over again. Without writing things down, I miss obvious and important problems. Very envious of people who can maintain a large system in their head.
ADHD forces depth first search ("hyper focus") with a time penalty to avoid sinking too much into one effort. It's just a different search algorithm that will explore the problem landscape differently.
I mean, how important is the pen as a tool to human history? The pen is one of the most important human inventions and the fountain pen is by far the coolest version of it :P
Most pens either ship with or will work with a piston converter. You don't need to mod a pen just to use inks other than those available in compatible cartridges.
A lot of people just reuse empty cartridges a few times by refilling them with a blunt tip syringe (sold by most online pen/ink shops), using whatever ink they want.
It is far easier to get a blunt nosed syringe for $0.10 (not sharpened for medical use) and use it to quickly and cleanly refill cartridges with whatever ink you want.
For a video visualization of how this works, Brian Goulet (who runs a popular fountain pen YouTube channel) published a tutorial on cartridge cleaning and refills: https://youtu.be/QloRQWHe5Gk?t=301
