And here is a render of some 100 stacked photos. Rough I know, but I can see the potential (the first (above) taken with Helicon Remote, the second with Remote and auto-focus bracketing, transferring to Focus to render)
Okay, here's the rough result (straight from camera with just some Aperture auto-adjust). I set it to take 103 photos, of which I rendered some 95. It needs some work, clearly, but I can see where I'm going.
Looks like I am coming down in favour of Helicon Remote and Helicon Focus for taking stacked photos and stacking them. It's not free, though. This was the first photo I took (I'm about to play some more...):