If you are using 'Inner edge' or "reference line' zones, then these are associated to the zone boundaries (wall or lines).
So if you dimension those boundaries then your dimensions will update as you adjust them - remember to 'update' zones as well.
Manually placed zones is another matter.
Yes it would be nice if the dimensions associated to the zone nodes.
I have also added a poll to your wish so don't forget to vote yourself.
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