The biggest contribution that I can think of is spending quality time distilling the true value of a project into succinct, easy to understand, practical langua

The biggest contribution that I can think of is spending quality time distilling the true value of a project into succinct, easy to understand, practical language and then (as a technical former-coder) building clear startup / path to use instructions. Failing that - stand up the code base and help with the README? I'd also second the gardening / community management effort. It's very important but I wouldn't get too general - keep up your technical / code chops so you can still truly distill things across all the audiences you need.