I’d say it depends on how impactful the change is. You first sculpt in Dynamic Topology to have a lot of freedom to deform and radically change your shape. If the changes are subtle enough, such as you are describing, then I’d say the retopo model is good enough to work on for those changes. And yes, what you do on this stage of the process will impact what comes later, but if you’re happy with your retopo and you only want to refine certain traits, after you tweak and move on, you shouldn’t worry about the fact that you refined some things right now, once you call it done you can move forward.
