I've never used the VC, but I would bet that the settings would not stick. Unowned community lots do not save. You can stick around on an unowned lot long enough for weeds to grow, but they'll be gone the next time you show up. Same if you break something or turn the radio on or off or set the kitchen on fire. I can't think why the Visitor Controller would work any differently, since no info is saved.

You can place the controllers, but you need a sim to set them. I guess every time you sent a sim there you could set it, but as esme said, it will not save and you would need to have your sim click on it everytime to reset it. If a sim owned the lot and set it and saved before leaving and selling the lot back, the setting should remain set.

You don't need to be in control of the lot anyway. You can spawn the controller on any lot by clicking Adjust... Visitor controller on any controllable sim. The settings do stick once you leave the lot, that's why if you pull the VC out of your downloads folder, all of your sims get reset and jump out of their beds and back from work.

It's the one thing I wish the VC had, a setting to make the settings stick as default, or be copied across all lots.