As the title says, it seems to be impossible to use the customization options in simulation mode to create a StructureNuker. Clicking a space simply does nothing. (I have tried in both Chrome and Firefox.)

As a workaround, it is possible to create a flag in a room you can see, and then (on the next tick) use setPosition to place it into any room.

Well, thank you for that, at least. That takes the point out of the strongly-worded post I was just about to make.

For other readers, in case you're wondering: I accidentally made all my reservers stop working, and the novice area appeared just an hour and a half after the last reservation ran out (while I was asleep, as it happened). Seemed almost like the powers-that-be had been waiting to spring into action to lock out my rooms, but I guess it was just bad timing (and not checking the history when they really should've).

(And, well, as long as we're examining the wording of the other post, I would still like to point out that it says "reserved rooms are also excluded", implying that reserved rooms and mined rooms are on equal footing when it comes to novice area selection.)

Yes, please explain. This is very strange and unfortunate. This cuts off the great majority of my mining from that room (which is my original starting room, no less)!

You can kind of do this by just decreasing the size in your browser, but it gets really slow. I guess if the page actually had zooming functionality, it could do something nice like stop displaying all the dynamically updated creeps past a certain zoom level.