I agree with the posters who say not to be concerned about usage patterns too much, at least with the way things stand at the moment.
However, if it ever becomes an issue, my plan is to have 2 flower rooms on opposite 12/12 schedules, giving a constant drain, rather than 12 hours of high usage.
As for veg, 18/6 isn't necessary. You could easily veg at 24/0, and I hear that quite a few people are using a 12/1 schedule with some success (like 12/12, but with 1 hour of light during the night to prevent flowering), so it seems like veg lighting can pretty much be manipulated at will, as long as the plants don't get a long dark period.
As others have said, implementing changes to hide usage patterns is probably not necessary at this point in time. It never hurts to think about these things though. You never know what the fuckers will do next to catch growers out.
