I'm asking this question because I want to suggest a solution, one where he doesn't have to touch his mouse but he also gets modern IDE features without a ton of setup. I used vim in the past and was able to get these features for Python but I remember it was rather arduous. Later, I just switched the VS code and decided I didn't really mind moving my mouse.
The language is primarily Typescript. The platform is OS X. I'm hoping there is some combination of (IDE + extension) or (vim + config) where he can just try it out and get the listed features out of the box.
I use it and develop in Typescript, TSX, etc. I've never found it lacking when compared to VS Code
You will probably have better luck on StackOverflow if they still permit questions about tooling and SuperUser if they do not.