Hi Dynamicweb,
Great work with Rapido! I have experienced that choosing UOM does not work on list and detail view.
Please try to test her: http://rapidodemo.dynamicweb-cms.com/Default.aspx?ID=52&ProductID=PROD62 (See video here for both product list and detail: https://www.screencast.com/t/bBdhXpH6BRo)
Best regards, Anders