Haven't really read thru this thread yet but in response to the original question,..always have been taught and utilized scaffolds over the use of ladders,...I found out a long long time ago you can get much more work done alot faster when you can walk the span of a walkboard instead of doing all the work you can reach from the singular workspace a ladder provides,..999 times out of a thousand its not that much more time to move a good scaffold than, it is to move a ladder,..the amount of work you can do off a scaffold is relative to the length of the walkboard whereas the amount you can do off a ladder is restricted to arms length in either direction IF you are ambidextrous.999 times out of a thousand you'll spend twice as much time moving and running up a ladder as you would doing it off a scaffold.,..the only thing better than a scaffold is a motorized lift ( I call them push button scaffolds)
edited to add I personally use a bergendorf paper hanging stage whenever possible,either with the hangers and or ladder jacks,....usually on jobs less than 12 feet I use the stage part with two step ladders,..the walkboard weighs 44 pounds and has a twenty foot long working area,...the whole unit (designed to use on billboards) with both hangers and saftey rail only weighs 88 lbs. it was the best $1000 I ever spent(1985 price) still use it on a regular basis after 25 years in fact I used it this past week,...