@Klaus, yes, you’re right. I failed to realize that in the new CDM the denominator in drug_strength is always normalized to 1, so both types of fields can be treated the same way as you demonstrated. We just have to be very sure that the denominator unit in drug_strength equals the quantity unit in drug_exposure. (That could be a check in Achilles Heel).
I’m all for adding records for every ingredient to drug_strength with amount_value = 1. That will solve the issue I raised for point 3 (when no matching clinical or branded drug is available in the vocab).