One of the things I actually considered adding to the EZ Omega was a "Themes" folder which would load up a bunch of graphics files and some config files into PSRAM at start. It did seem a good deal of work without a lot of payoff. But, I guess if one were to make something like a "graphics pack" format based on the EZ4 skin format with extensions for the EZ Omega it'd be easier to parse on the kernel end (ie, fewer sanity checks).
Again, though, that still seems like a lot of work with little payoff, but throwing the idea out there if you'd want to give it a go. The cleaner method of course would probably the reverse--extract out theme elements from EZ4 skins into graphics files and config files so you could import them into some standard ez omega format. There's definitely enough PSRAM for it. The only real hard part is dealing with the loading screen graphics and possible failed loads requiring to reload the theme when usually a failed load means there's issues reading from the microSD. That last part is basically a guaranteed hard lock anyways, so more of an annoyance that it can't be fixed.