Great article! It has been very helpful. Regarding the extension of Next's Link props, could you do something like this?
import NextLink, { LinkProps as NextLinkProps } from 'next/link';
type InternalLinkProps = React.HTMLAttributes<HTMLAnchorElement> & NextLinkProps;
As of what I've tried, it seems to be working fine. I have to say though that I have very little experience with Typescript so I might be missing something important here.