Actually this might kill a few birds with one stone.
There's been some talk of having editor hooks that would allow for third parties to create ways to interact with the editor. Hopefully this would be something that would bring a richer experience to the editor, and allow for some things to be setup in-editor rather than having to do that at run-time. However this brings up quite a few issues, development, security, and bugs out the wazoo. So it's fairly easy to understand any reluctance to do this.
Workarounds now are to either make events to do that, or load an objects state as json.
I think you might see where I'm going here...
What if we had options to load those json files in editor, for all objects in their preferences?
Tilemap. Instead of trying to make a file in Tiled, and load it via tmx you use a json state.
Sprite. Position, z, angle ect.
Particle. Options preset, individual particles preset.
Timelines. Boom.
Arrays...
Obviously this means that those objects states would have to be exactly the same at the start of the runtime, as they are in the editor.
This actually solves a couple of my existing feature requests.
Of course there would be limits, textures would obviously not be included, and mixing and matching would not be advisable, etc.
Yes, no, maybe?