Re: Edge3 Replacement Tremolo (no mod-free upgrade except EdgePro)
The Edge nut on my Jem 777 doesn't match the width of the neck, the Floyd Rose nut on my Strat also doesn't match it, though both have proper string spacing and radius isn't an issue. Regarding the Floyd Rose Pro, I actually fitted one on my Strat last week to replace my Schaller style Floyd Rose II. The supplied nut (about 40mm) with the Floyd Pro was the same as the previous nut but the trem is definitely narrower string spacing and you can notice it, depending on your preference it could be seen as a good thing but it's definitely a difference.
I haven't got an Edge III or Edge pro to measure but the string spacing on an Original Edge or OFR is roughly 4mm wider than on a Floyd Rose Pro. The Floyd 1000 Pro is the Korean version and that shares the standard OFR string spacing. Also worth noting is that unlike a Schaller or OFR design the Pro versions are a bit like an Ibanez Lo-Pro, all of the fine tuning parts route through the trem and hang underneath it lower than the base plate and need more space under the trem to move, it might not be an issue on an Ibanez though since their back routes are huge but it takes up more room than an OFR.
Just get a Gotoh GE1996T and route it if you need to make space.