Certainly a good recommendation but not required based on what I mentioned above 
Your action mappings look good but not your state ones. You are defining closed state as 1% and open state as a range from 0% to 100%. Obviously there is a conflit here although since it’s not really used on the Alexa side as of yet, it doesn’t affect your interaction. Anyway, here is how I would update your item definition:
{alexa="RangeController.rangeValue" [category="INTERIOR_BLIND", friendlyNames="@Setting.Opening", supportedRange="0:100:10", unitOfMeasure="Percent", actionMappings="Close=100,Open=0,Lower=(+10),Raise=(-10)", stateMappings="Closed=100,Open=0:99"]}