It doesn't stop requiring videogame logic just because there's no "gameplay" objective. Even "it's interactive" doesn't have any standard definition, do you interact with it by proximity? How far away? By clicking it? By pressing a hotkey when you're near it? By pulling a lever? Do you need an item or some other prerequisite? Does it cause something else to trigger elsewhere? There's no single solution that accounts for all possibilities, so you have to script it in.
It doesn't sound complicated though, I'm sure those engines have very simple ways to accomplish what you want, but I suspect it requires writing some code anyway. I'm not very familiar with the engines so I can't say exactly what.