That is a cool idea...but those 2 roosts are awfully close together!
@micstrachan : though it wouldn't have wheels, an easy/quick roost might be one of those inexpensive plastic folding tables...with roosts  like this on it.
2 of these...and you could later put them in the run, once you have more permanent roosts in the coop, for 'run enhancements'
https://www.oceanstatejoblot.com/enduro-4-steel-frame-folding-table/product/222820
https://www.oceanstatejoblot.com/enduro-6-folding-banquet-table/product/222819
I don't know if you have an Ocean State Job lot out there, but you probably have something similar where you could get these very reasonable.