I would like to see the ability to regrade when you change an algorithmic variable. In a perfect world you don't make mistakes in calculations but I was unable to regrade a question when the difference was a mere - rather than a + in the formula being used ultimately to assign to $answer. I was informed this was not regradable.
Due to cloning and editting a variation of a working question I missed one sign. This does not change what the students saw displayed nor did it change anything in the question code apart from what got handed to Maple to evaluate and then the final results handed to $answer. From the students perspective nothing changed. This seems like an obvious thing to implement. Webwork can do this. The handwritten equivalency is to make a change to your answer key which is something most instructors I know do from time to time.