Yes, the cave collapse trips up macro users sometimes. It's frequency of about once an hour isn't as much of a deterrent as it could be.
Yes, grabbing and moving a suspected macro user is the most common method used by the admins to check a suspected macro user.
I really wish this thread's discussion turned more back to the question of the merits of turning the cave spiders back on rather than how do you catch a macro user.
My goal was to make disruptions frequent enough that no one get much of a benefit in using a simplistic macro. Which would then discourage their use.
I should also have mentioned in my original post that redesignating portions of the mine where corners are to be areas that wont work to drill in both directions would eliminate the most simple macro where the person doesn't even move, just mines in a corner. When the mine collapses or they are killed they warp to a hospital making it harder to see that they were using a macro but if you were at the hospital you would see them drilling in the hospital.