Rob: I think pretty much all of them
I think I have 2 issues with that way of thinking expressed in this thread:
1) It implies that people are letting a computer control their dive.
I think that it's excellent not to push to 1.4 given the large variance in O2 exposure limits, but why not just work out a max depth using some tables and _know_ the other criteria?

2) If you read through the link I posted, high ppO2 exposures early in the dive and for short times seem to have very few ill effects.
I think this is key, for instance, what if someones buddy has an issue at the beginning of a dive and blows a max depth based on ppO2? What will drive someones decision to go after their buddy if it means a ppO2 of 1.8? Or 2.0? And it's early in the dive? I think that these type of things are important to think about, which is why I posed the link in my previous thread
I used to do exactly what people here did, which is to say that I'll just set this conservative hard ppO2 limit and that's it. But then as I read more and tried to understand more, I started to realize just how much more there is to it than is discussed in the Nitrox course
If you get a chance, read the posts on rebreatherworld, I took much away from the discussion and it made me critically evaluate some assumptions I'd made
Heck, maybe I'm just slow and everyone else has already worked it all out.
Must run, going diving (at a ppO2 of something like 0.6

)
Dive safe.
Bjorn