I think the best solution (as in the least number of people will be sobbing in the corner calling you a heartless, terrorist, brute and urinating on themselves) would be a compromise.
All technologies are in.
However, any technologies discovered won’t come into play until the collect income phase.
This way the sobsters out there moaning about Long Range Aircraft suddenly sinking all their boats (which, btw, you won’t need to roll dice for, and you won’t even have to luck out and get the LRA tech, it’ll all be automatic) will not have to ever compensate for the technology coming into play by making sure they have enough boats to protect themselves or are sufficiently far away that even if the enemy does get LRA they won’t be able to bring every blasted plane to bear on them.
Honestly, I think it’s just bad play if you have not looked at the board and said: “If they get this tech, I might be in trouble. Should I go here, or there? Well, if I go here and they get the tech I’m screwed, but i can recover, so it’s worth the risk they’ll just waste the money and not get the tech or if they do get a tech, they’ll get one of the other 5 and not the one I’m worried about.”