I made yet another animation. Here I've created two switches, each one hooked to the three blue sectors with the trigger type "mover lower". This lowers the floor height of the sectors until they match the next highest one and there's also the option to switch the floor graphic when it finishes(here I have it on). In the animation I've walked over to one switch and then walked back so you can see both of them, it's hard to see them when close so I probably won't use them that much.
The only sector effect left is stair builders which should be a total bitch. Then it's on to spawner / teleportation triggers.