Pushing is an iffy thing....(posted 8507 days ago)The fact is that upon extended development there's no useful increase in shadow density, just increased contrast; the reason for extending development is so the neg will print on a "normal" paper of grade 2-3 rather than needing, say, grade 5.
Also of course how you meter the scene and the brightness range of the scene are major factors; could be you used EI 1600 and I might meter the same scene and come up with the same camera settings using EI 400...or vice-versa.
The developer you use of course has an effect; if you use the traditional .10 DU above fb&f as the speedpoint, you'll find that HP5+ in Microdol-X is EI 200 at best, it's EI 400 in D-76H 1:1 and it's EI 640 in Microphen.
I don't know the context in which Nocon's writing, but the _fact_ that various films give different speeds in different developers pretty much nukes his assertion. Within limits what he recommends would work in that most likly all negs would be _usable_ but there's a big difference between usable and _good_.
There's really no such thing as latitude, whether it's a traditional film, chromogenic or whatever; there's only the correct exposure and development for the scene brightness range and the materials it'll be printed on. While you can certainly give more or less exposure and development you'll be losing a little quality if you do.