Since minecraft is capable of drawing an outline with an structure block feature, i think its possible to use that in World Edit as well. I would love to see that outline of an region u selected or the selection of position 1 and position 2.

Iam not sure if other shapes are possible this way, but square selections are most common to my knowledge.

visualisation:
https://i.imgur.com/gbyOWbG.jpg

//drawsel