Whereas I don't check my own structure count against controller level (yet), I do check enemy active structures and plan my sieges off that. This obviously doesn't happen often, but in some rooms it's a bit funky, especially with the bug you mentioned.

I feel this is also a great way to test out new attack code. For those of us that don't like attacking neighbors or don't have any hostile neighbors to attack, this would be a great opportunity to do that.

In addition, it could pose as another barrier to slow the progress of expansion. A stronghold on the path to your new room may require you to send more than just a 1x MOVE 1x CLAIM creep.