To compress non used textures in memory (If set)?
Sorry, can't remember that...i guess, i'm just getting old. Well, i don't really see a large point for the desktop version. On the desktop, you actually need the stored texture data much less than on Android with it's sucky Activity management. So you usually can get away with simply setting the option to store them to false....that's unless you are using the software renderer, but that one would need them anyway. So the only benefit would be to compress texture data that the software renderer doesn't need right now. But that would be a complete different logic than what AE does now and requires some kind of texture management component, that currently just isn't there.
In conclusion: Can you show me a situation where this is actually needed on the desktop? If so, i might reconsider adding it.