I never interviewed Curry, but for GENERATIONS, I had two very lengthy interviews with Ronald Moore (VFX Moore, not writ/prod Moore) where we covered lots of TNG TV stuff as well as the feature (there was some thought to doing a 'storyboard to completed shot' style book on the VFX, which Curry had been pursuing for awhile, but when Moore approached him again, there was some reason he didn't want to go ahead.)
I don't remember now if Moore was Curry's VFX coordinator or Legato's, but the 30fps thing came up a couple times, and it seemed that it was an expediency thing, like you could get it through post faster for some reason.
Something that hasn't come up very often about TNG VFX is that they were budgeted for only a tiny fraction of each ep's budget. For the first couple of years, I think the pattern was somewhere around 70,000 per ep (out of a budget that was 1.2 mil or thereabouts), which if you adjust for inflation means they may have been doing the work for less than TOS in some instances. (Also kinda makes you wonder where the money went if they were spending over 1.1 mil on the non-vfx aspects.)
Several years back I tried to find a way to get all those old transcripts from GEN and FC off the 3.5" floppies, but since it was done in a weird file format (I used one of those electronic typewriter thingies rather than a computer almost up till the end of the century), I couldn't salvage anything. I have maybe a thousand cut words from the GEN article on hard copy, but nothing relevant to this issue, unfortunately.