Agree with a lot of points here, especially minimal unit tests against demo inputs, especially when the real analysis takes a while to run.
I do want to add that my hesitation against unit tests has a lot to do with how much refactoring I’m doing as I go through the project. It would be great to include when submitting code to accompany a paper, where the analysis is relatively fixed, but seems more questionable in day-to-day work.
It also makes sense to me that code review to help someone debug is going to look different to code review to make sure results are computational reproducible.