"I bought inexpensive scaffolding..." I believe something like that is the right concept. However, when I tried a version of that it was a huge disappointment. The articulating ladder shown below proved to be extremely awkward in practice for anything. Even as a simple folding ladder it was never the right height, was WAY too hard to open and close in tight quarters, and the legs were too narrow to provide much stability. As a platform it had the same problems, plus making me extremely nervous that the whole shebang might collapse any moment as I crawled toward the unsupported center. It did not collapse but I'm not desperate enough to try it twice. If the upright parts of the legs were adjustable and the center hinge was stronger it might have been an elegant solution, but this was a fail for me.
I forgot to mention that, at the time I tried this folding mess, a huge criteria for me was portability, and it still is, as I mostly work on-site from a minivan. Scaffolding and a plank take up a lot of room. I think Little Giant needs to get on this problem and come up with a truly elegant solution that solves all the problems mentioned above. Anybody else have tricks or rigs that make this easier to reach?