Greenscreen was commonly used from about TRUE LIES onward, for film projects as well as others. What is of interest in this case is that if you look at shots from making of INS, the collector set utilized GREENSCREEN at the bottom. Why put bluescreen around the sides if you have greenscreen at the bottom? NO REASON WHATSOEVER. So the blue was an 'artistic' choice, albeit a sucky one, just like all those cookie-cutter hex shapes all over the Son'a ships.
The notion that any effects comps were cut due to cost issues are ludicrous, since Par was willing and able to spend between 7 & 12 mil in the last few weeks before release to fix the perceived faults, driving the budget up from the 58mil that Berman started admitting was the ACTUAL cost as soon as they saw the movie wasn't going to do the business that would let them say it cost 65-70mil.
[petty personal stuff snipped for space]