At Anderson, every faculty seems to have a different technique. Some do a single burn lateral to the foramina at S1,2,3, some do a strip lesion with bipolar just medial to the joint line. ASRA published a technique doing three bipolar lesions around each of the three foramina which seems to make a lot of sense. I'm planning on trying this technique on my next SI RF.
Given the variability of innervation of the SI joint as well as the significant contribution of nerves running along the anterior sacrum, SI RF seems not likely to have the same kind of reliability as facet RF.