[Media] What's a feature you suffered on but nobody noticed

I'll start. I'm building a paint app and wanted to have a stabilizer effect like in Procreate. I underestimated how much engineering goes into a feature like that.

Basically, months of engineering and trial and error (AI helped but not nearly as much as I would have liked) for that feature, which has very little practical value, except if I'm lucky, somebody will be like, "huh that feels kinda neat".

The way it works is when you draw with the stylus, it captures the raw input events and stores them as a vector in memory. Every frame, the vector goes through a laplacian algorithm to smooth out the kinks and jagged edges, and that smoothed version gets diffed against the previous smoothed version. Whichever part of the stroke changed between the two, gets erased and redrawn along the new line. That happens sixty times per second, and thanks to some clever shaders and the wgpu library, manages to run smoothly in webassembly.

Demo https://app.darkly.art/
Github https://github.com/darkly-art/darkly

What's your most underappreciated feature.