The hitch is, narrative aspects shouldn't have mechanical consequences. Describing things narratively is one thing, but enacting mechanical repercussions based solely on narrative measures is kind of bad. It unbalances mechanics. And while I understand most games aren't super-well balanced, unbalancing them even further isn't advantageous.
But as for narrative vs. mechanical, let's use Food as an example.
Narratively, you can say that at Food 0 the stockpiles are gone. People are going to start starving, and there is a lot of panic. However, mechanically, it impacts the Session Body Count the same as Food of 9. You wouldn't increase the Session Body Count arbitrarily between the two scores. So yes, mechanically the results of a 0 and a 9 are equal. You roll a d6 at the end of a session (whatever we determine that to be in PbP of course) and apply no modifiers.
Nothing "just appears." The projects are there to improve the arc, but let's say we finish the Hunting Parties project. It gives +2d6 to food. But we roll snakeeyes. So we add +2 to our Food development level. Yes, we narrate that we started hunting for food... but until that Food score hits 10, there are no mechanical benefits from the +2 we added.
[ +- ] Also...
We won't get into a more narrative point that a person can go three weeks without food, so even if we had Food 0 no one should be dying of starvation for at least about 2 1/2 weeks of in-game time.
All that being said, if we want to say "screw the rules" and go for some houserule shenanigans where every point of rating matters, that's fine too -- but is something to have brought up in the pitch, IMO. As for discrepencies between the number of successes... remember that this system doesn't usually have a ton of successes (1 to 3 seems typical, barring crazy rolls). We should also remember that most rolls already outline what happens in the event of multiple successes, because the player "spends" them for additional results.
Last note: From a personal standpoint, I've had exactly one excursion into the zone in a short lived game myself and Pedrop were both in. I'm in favor of sticking to the rules, just because I'm still learning them.