I'm going off the guidance leaflets from the insolvency service rather than the legislation but I really think you are making too much of this. If you are concerned i would write to the CCCS and get a written response from them.
DROs are a form of insolvency - albeit you don't have to go to court. There is a 12 month "freeze" on all named creditors and then they will be discharged. No one can come after you for a shortfall as far as i can see - it clearly says the OR will contact all the creditors named, the amount is irrelevant as far as I can see unless your circumstances change in which case you can resume payments.
After that 12 month "freeze" if your circumstances haven't changed the named debts are discharged.
Unless someone says differently, there would be a heck of a struggle if after I'd done a DRO someone tried to chase me for a debt.
I don't think you will be liable for the difference.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
