Oginme, thanks for looking.
Right now my mash profile is set to "BIAB, Medium Body." The Sparge field on the Mash tab no longer reads "Fly Sparge..." It's showing "If steeping, remove grains, and prepare to boil wort." So definitely some progress. But the Water Adjustment Salts section is still split into mash and sparge additions. I've tried changing the target profile to other targets and back, hoping BS would then recalculate based on my updated mash profile. But it continues to show me both the mash and sparge adjustments.