Well I went and shot the moon with my recently acquired 800mm f/5.6 setup (SMC A* 400mm F/2.8 ED [IF] + SMC A 2X-L converter). I went out 3 nights in an attempt to see if I could figure out how to combine shots to get an expanded terminator shot and still haven't figured that out. However here is what I was able to pull out of 338 shots stacked in Hugin. Each shot was shot at ISO 400, 1/400s f/11 (f/5.6 plus the 2x converter for 11).
The stacking was done in batches first combining sets of 18 or 19 (I did 18 sets) images using enfuse favoring contrast (contrast weight of 1 with saturation and exposure weight at .1). The I combined those 18 results using hugin_stacker with a mode of average to clean up the noise. Alignment and remapping of images was done in hugin. Final processing, cropping, resizing, and final sharpening was done in GIMP.
Cross posted in the 300mm+ thread.