Yes, the fact that you can only sort on the second field in this case is very frustrating at times, especially when other competing systems do not have this limitation. In fact, another system I have used allows you to refer to a completely different field from those that are used for data-entry for determining the sort order--as well as having many more than just two columns of data.
You seem to have correctly identified the trade offs between basing values on a table vs. using a custom value list, except for this statement: "it makes it difficult or impossible to do sub-summary reports based on these values" I don't see why it makes much difference whether you use custom values or table base values in a value list for how you set up sub-summary parts in a summary report.
Thanks, I see now that it doesn't matter where the values in fields are coming from (tables or value lists), since sub-summary reports are based on a field that is sorted. I stand corrected. Thanks again.
It has been three years and still not a fix