Understood, thanks. Just have a situation where interrupt the construction of alien bases are not favorable, and the ship "delicious" landed. Have to let go.
There's a way to get virtually any outcome you want.
A.) Alien base never fails to be built
- METHOD: don't use interruption on Alien Base or Alien Infiltration mission
B.) Countries can be prevented from leaving the project, but alien bases still get built
- METHOD 1: increase weights for Alien Base mission (make non-interruptible), decrease weights for Alien Infiltration mission (make interruptible)
- METHOD 2: allow countries to rejoin when base is destroyed
- METHOD 3 (ADVANCED): edit Alien Infiltration mission to change the base that it builds or make it not even build a base at all
C.) Infiltration is interrupted by shooting the craft down, but not by taking them on land
- METHOD: Add a wave of three UFOs after the final craft, on a timer of perhaps 60 (try different values and see). You want the final UFO to spawn on the globe around the same time as the big UFOs start landing. (My mod has the timer at 240 which has been well-timed to make the base appear during and towards the end of the landing event.)
PM me if you want more details on how to do one of these, or if you have a different functionality goal.
edit: I tested some timers and I think 60 is fairly good for the final 3 ships. That means you get about 3 hours from appearance of the Battleship until the base is built and the infiltration is completed. Time variation can be anywhere from 1.5 to 4.5 hours but will tend toward the center. In my run, the battleship took ~3.5 hours to land, and other ships were already landing by the time it arrived.