Ashley recently optimized the destroying of objects specifically for this. Loading on the other hand might cause a slight hiccup if your zones are huge but, as you said, lazying loading can fix that or the dev can put in some sort of transition.
The creation & destruction of objects is necessary to "reset" them when re-entering a room or zone, and making sure that nothing is going on outside of the current room or zone. What better way than just destroying them and calling them back when needed? Instead we got this new action that doesn't really apply here...
Layer zone isn't a bad idea either but you'd then have to specify the object types for each layer so that's a no-go.