Hmmm, this is pretty good idea. I think this can be split into 2 uses.
Make a project setting of supported devices. This shares to the hub, and when you play it in the hub it also preserves the device it is desiged for (I think in this case it should auto default to the one closest to your current aspect ratio).
An editor setting, to automatically select the desired aspect ratio when running the project from the editor. This way you can quickly test with out always having to switch aspect ratios.
Of course in both situations the available aspect ratios will be selectable from the in game menu as it is now.
Does this idea solve your problem?