It took me several attempts to complete my RFC. The doctored ordered the PT to do it, and then the doc later filled out separate paperwork using the data the PT had documented.

I have RSD, and anytime I engage my dominate hand it swells. So, the PT would first put my hand in water to determine volume, then I would do a task until I hit a certain a fairly high pain threshold--basically a few minutes of typing or writing, etc., and then he'd remeasure my hand for swelling. Frankly, I was with a PT that hadn't had an RSD patient, and the testing showed the PT that my subjective complaints were in line with a physical reaction. But honestly, they got creative for my specific problems.

Different docs will be willing to put in more effort than others to try and help you. I had one promise he'd do whatever was required, and then balked when I had a tight deadline to get it done because he was in the middle of fighting his own legal case and didn't have time. When I pushed, he did a half donkeyed version and it hung me out to dry and delayed my approval a few more years... I learned that overkill on evidence from as many sources as possible was the best bet.