Hmmmmm........ I got a very nice and thoughtful reply from Zebralight regarding my question about why the lowest levels seem to be creeping upwards. Unfortunately, I didn't ask for permission to post their reply, but here is the gist of it, which I found quite interesting.
Maybe you'all already knew this, but apparently the SC600Fd III, and all 18650 lights released after that one, have a driver that has 2048 sublevels, many which are much lower than the ones published on the ZL website. Their choice of .2 for the SC600w IV Plus lowest level has nothing to do with limitations imposed by the LED or driver, but is a conscious choice on the their part to set the 12 allotted user levels so that they are spaced "perfectly to the human eyes".
Evidently, as the output of the LED increases, it becomes increasingly difficult to maintain that optimum spacing, requiring them to increase the lowest levels a bit to fit in with that model.
I find this fascinating, and also hopeful. It seems clear that if enough folks ask them to reduce the loweset output levels, at least a bit, then they might be willing to do that. Well, I've done my part (hint hint nudge nudge).
In any case, I'm continually impressed with ZL and their thoughtful approach to portable lighting, and will look forward to getting this newest version for my small, but potent collection.