For Responses and Factors (where appropriate) I would like an extra field to specify the Units that Responses are measured in and Factors are set at. Like Lower/Upper Limit for Responses and Role or Changes for Factors the specified Units would be saved to the Column Properties for that column.
When deciding upon the Values for Factors to use in the DOE one automatically thinks about the Value's Units anyway and it would be easy to enter them here, whereas later on in the data table many people don't bother entering Units (one reason being that one has to go into each column's properties one by one unless all Units are identical, which is rarely the case).