I've also found out that you can't even reorder channels within the multi-out plug itself without reassigning parts to new outputs, even when no buss has been created.
This is madness!
Using Impact for example with 8 mono outs, whatever order I originally loaded sounds in/assigned outputs for, I'm stuck with in the console view. So if I loaded a kick to mono out 1, snare to mono out 2 etc, but then later added a 2nd snare layer to mono out 6, I can't move that snare layer next to the original one in the console. It's always going to be the 6th channel along.
The only way to change the order is to reassign that 2nd snare layer to mono out 3, move whatever inserts were on mono 3 to another channel, and then drag the new layer's channel settings over from mono 6, manually set send levels again etc.