@judgedread @LatigoMorgan Correct, you should not stop gatekeeping just because there is a possibility of someone making it past.

Frankly militaries have been concerned about this for ages, so there is a wealth of information on this.

But the thing I like the best is flipping spys so they become spys for you - because they are some of the hardest for a enemy to stop, because they need to give them latitude.