This is a minor issue, as most people *with not that good computer* do, the tiny lumber mill is so tiny that we may misplace it, and worse, when you cancel it, you does not get it back.. Worse, it is a level 4 tiny lumber mill.. Worse? that is the last piece of lumber mill needed for lv 7 mill XD
So, small suggestion: Make Tiny lumber mills to drop as item when is cancelled by player or by base-claim-protection trigger, if it is destroyed by attack of course it will not drop as item