With new builds, Version still 12.0.0 so likely installer refinements?
Don't do the en-masse mapping unless you have few historical meds. I had 1200, majority old discontinued stuff. Anything ever prescribed (that doesn't have an automatch) has to be mapped. I did do all the allergy mapping in one go.
Then I think it's more reasonable to just click on each patient for the next week's schedule and hit meds. Reconcile 1 pt at a time. After I did 3 weeks of schedule in ~1.5 hrs it becomes less and less onerous as your most common unmatched items get matched.
Worst for me is the many old glucometer models and insulin needle types. I wish I could automap them to "glucometer, strip, pen needle, lancet of choice".