I'd put that under 2.5 or 3.5, if not later. You only really need to do it before you start modifying code, and it's a massive effort to understand a new codeba

I'd put that under 2.5 or 3.5, if not later. You only really need to do it before you start modifying code, and it's a massive effort to understand a new codebase. Better pick the lower-hanging fruit (like corruption bugs) so you can at least stay sane when you run the tests and try to understand them.