mmh, but what if you can let your robot pet (which you can assign to your construct and is only activ if the player is near his construct) do the chore stuff, but if you do it yourself, you get that temporarily stats bonus. Both need certain skills and for balance reasons I would suggest that 1 player can use only 1 maintance pet, so the pet can work like a LUA scriptable passiv skill. Meanwhile the pet need maintance/(atleast some attention) itself by the player.
Another thought is that maintance could get a "new" job/specialastion and it would make players take more care about there constructs so they would have less contructs, which need more attention, which should increase perfomance in a way.
I remember a discussion about spacescrap/debris despawning in a certain amount if time. Perhaps this mechanic would embelish it.