I have a larger music performance/music shop that has a pretty extreme load swing. When they are just using the space as a show room, the load is low but when they pack the place with 300 people and a live band, the need a lot more. They have 3 units and I just set up a 3 heat 3 cool Honeywell programable with some relays to control the staging. I think it wouldn't be too hard to add an extra "stage" with a time delay. The easiest way I have found is to build a control center with all your relays and transformer and mount that indoors that way your wiring isn't a mess. All of the connections can be made in the box and then a wire to each unit and one to the stat. Looks nice and performs nice.