I've just finished my first playthrough and was surprised to note that when I prepared for the penultimate mission, the option to spend intel for various special effects was available – increase the squad size, better concealment, etc. I never noticed this on any other mission, but it seems a neat concept and it struck me as unlikely that there would only be one mission in the entire game where this is possible.
I am thinking that maybe the options were never presented the rest of the time because I tended to be running at very low intel, spending it immediately on things from the black market, but by chance I had intel at about 300 going into that mission (playing on normal). Was I just missing the options the rest of the time or is it really the case that this is the only mission you can spend intel on?
Best Answer
This really is the only mission you can spend intel on. (This mission will actually show all of its options regardless of how much intel you have. I used this to spend time to gather more intel in my first playthrough.)
At some level it make sense - the penultimate mission is a planned strike, that XCOM would have time to prepare for. The only other missions like that are the facility strikes and blacksite investigations, but those are all in remote areas that would be very difficult to perform recon on without being detected. The penultimate mission appears to take place in a city center, where one could presumably gather intelligence for some time prior to an assault.