Unfortunately there are potential issues with both scenarios. If a database doesn't include UOM, when it is imported into the destination, someone has to either use the UOM at the destination and make adjustments as necessary, or risk the potential for wrong day, such as Formulas or Analyses. Therefore by enabling this idea, we can inadvertently create other issues. As such, we have no plans to implement this idea at this time.
Our recommendation is for both source and destination to have the same UOM conversions.