Accumulate & Past Values

I ran into a gotcha when using accumulate with multiple tables.

When the input hash already contains a column matching an output column, it is turned into an array. This means if your table has, say, two rows that match the input data, output columns that are new will have two values, and output columns that are not new will have three values. And the only way to determine how they are aligned is by inspecting the ordering of the columns in the decision table.

I can imagine circumstances where this would be what was desired, but when its not desirable it is difficult to work around.

Would it be useful to add an option, say, **accumulate-new** which replaces output columns on the first match and accumulates subsequent matches?