Atomic Frontier on YouTube trained a machine learning model on his prior emails, assignments, etc., and had it determine his personal worst keyboard layout. He posted the code on GitHub for others to do the same.

I second looking at System Crafters’ resources. One thing that helped me was their emacs from scratch video series.

And as a heavy Markdown user, I initially built my config around Markdown. But several years later I’ve found I now use org-mode almost exclusively instead. They both fill the same niche in my workflow, but org-mode can do a lot more.