1. Exportable to text file just like the rest of ground control actors.
2. Default name should be that of the two markers a scale bar links, for instance "point 1-point 2". A comprehensive link between a scale and the markers it has as end points, should survive to any renaming and/or must be explicit as a property of the scale bar
3. I'd rather prefer the old fashioned tool for picking scales on model window better than choosing two GCP and right click for calling contextual menu.
4. Scale bars could be exportable as segments in some cad formats. That would allow a primitive form of restitution.
Regards! and congrats for my favourite dev.team