I think we are on the same page AC, my thing is, 15% one way or the other isn't going to make a big deal. Your typical flash time is a wide open window much further than most use. So if the recommended flash is 20 min mininum and it is much hotter so the guy "should" cut the flash a little, waiting the full 20 isn't going to do a thing being the real window for recoat is much more, hours in most cases. That is my point.
The danger of speeding up the flash times is much more real than slowing them down. I have see VERY few failures do to waiting too long between coats, clears, yes,but not basecoat.