Agreed, refactoring and functional changes should certainly be in separate commits, and ideally in separate pull requests. jacquesm can still have her/his rule

Agreed, refactoring and functional changes should certainly be in separate commits, and ideally in separate pull requests. jacquesm can still have her/his rule to only change code involved in the course of functional changes; it's just that the refactoring and functional-change PRs will come in close succession and the refactoring PR exists only because the functional-change PR does also.