I believe the work-flow shown in the video is a workaround, not an expected behavior. What if, for instance, I don't want a user to be able to manage multiple UOMs? What's more, a user may select invalid UOM (it might be different from the one on a product) while adding a scheduled products. So he first has to check what UOM is on a product and only then he should select UOM. IMHO that's a usability bug.
I believe the work-flow shown in the video is a workaround, not an expected behavior. What if, for instance, I don't want a user to be able to manage multiple UOMs? What's more, a user may select invalid UOM (it might be different from the one on a product) while adding a scheduled products. So he first has to check what UOM is on a product and only then he should select UOM. IMHO that's a usability bug.