I don't think any of this stuff really matters for 1 person projects. The goal isn't to have multiple developers adding features in parallel with each other, s

I don't think any of this stuff really matters for 1 person projects. The goal isn't to have multiple developers adding features in parallel with each other, so if the author understands it, it's more than likely OK. I wouldn't pick that language, but they wrote Roller Coaster Tycoon in pure assembly and wrote Emacs in Lisp 40 years ago (and we're still using the code today), so this likely won't be a project-killing decision. I would take Emacs Lisp over Typescript any day, but that's just me.