Always Flyin,

I believe your assumption is correct. I recently went ORD-NRT-PVG with a 26 hour stopover in Tokyo. Because I was over the 24 maximum stopover limit, I would have needed to use another SW to upgrade the NRT-PVG portion from C to F.

However, I have heard that sometimes there are some special rules that apply to flight thru Tokyo...so maybe someone else can tell us if this was unique to Tokyo or standard practice. In my limited experience with SW upgrades certs., I don't ever believe that I've heard of anyone breaking on up on a stopover of more than 24 hours.