Really excellent report.
I would just observe a couple of things: the ‘higher requirement for visibility for some ILS’s’ is of course partly a factor of the approach speed. So not an entirely fair comparison.
I would also comment that Part 121 airplanes also spend a proportion of their flight close to the ground (and in some cases obstacles). So the inference that proximity to the ground is responsible for the difference in safety doesn’t quite work for me. It’s more to do with what mitigation’s exist for that? Fixed wing that are close to the ground are usually in protected radar controlled airspace, with a controlled set of parameters.
Finally, doesn’t the old adage ‘if you think safety is expensive, you wanna try having an accident’ apply? Just ask Boeing…