Right now the objects are hidden when they are not active, and they only appear when they are activated (by being triggered and by the timestamp).
But sometimes it's useful for it to be the other way around, and disappear when activated.
For example, it would be fun to make it so that the whole map starts disappearing as soon as you pick up some object and you have to run for your life to avoid sinking in the lava.
Another use for this would be for an object to disappear on activation when the player touches it (or gets close to it), as if it was an object that was picked up. We would need no more keys or apples to trigger events, we could make our own custom buttons and item-like objects this way.
Right now every possible puzzle has to happen in the same single room. You can't allow for the player to go grab a key or activate something in a room that can open a door or trigger a change in another, different room.
I think that a nice way to enable this in a way that's consistent would be using global object groups. Groups could have a "global name" property so that groups with the same name are in fact the same group, even if they are in different rooms.
When an object in a global group is activated, wherever it was, the active status would apply to all the objects in all the rooms that have the trigger set to "group" and are from the same group.
Something like this would be very useful for dungeon/maze-like kind of levels where you can go back and forth exploring the branches searching for a trigger or an object that will help you in another part of the dungeon. It would also allow for some kind of inventory, as the level will know if you did pick up something (or got next to it at some point).