The topic of "vintage stagger with flatter/compound radius boards" has been something I've been thinking about for quite a while. I spoke to Tim about it and he said he plays vintage stagger Apaches on a strat with a 7.25-16" compound radius (yes, that is pretty extreme!) without any problems.
I've also heard people on Fender forums comment that of all the single coils they've tried with vintage stagger, BKPs are the ones that perform best (ie. suffer least from volume discrepencies). I don't have any personal experience of this as currently my Apaches are fitted to a 7.25" radius strat neck, but I'm about to order a 10-14" compound radius neck so I'll let you know how it goes.
If anyone has any opinions on this, I'd be interested to hear them.
Cheers,
Jordan.