Once mapped, unless something changes with regards to the spec of the engine (ie swapping cams or turbo or whatever) I tend to just leave things alone more or less, there is no need to constantly revisit.

Obviously you'll always be tempted to the odd little tweak when you notice a stray AFR here or there when on cruise or whatever, but its only something you do because you WANT to do it, it shouldnt be anything you HAVE to do, if that makes sense?