To be clear, I know what your were talking about which is why I made the fundamental/functional distinction, as I have before. Expectations are irrelevant (particularly where idealism is concerned), a fundamentally idealistic reality does not preclude functional materialism. As you note in the post I quoted before, functional materialism does tend to introduce explanatory problems for fundamental idealism. Particularly in terms of consistency, but that doesn't, in and of itself, preclude an apparently and consistently functional materialism. So "the whole "under no circumstance would we expect a fundamentally idealistic universe to appear functionally materialistic"" is technically incorrect.
As I have asked before, what couldn't you expect under fundamental idealism? Other than just 'no consciousness', I can't imagine anything. As we do find what we refer to as consciousness, that singular condition has been met. That one might expect to find material inconsistencies in a fundamentally idealistic universe doesn't mean that must be that case. So while fundamentally materialism is falsifiable fundamental idealism isn't. As long as there are conscious entities to consider it.
However, a lack of falsifiablility ain't my main problem with idealism. It is the reliance upon and extension of something so tenuous as consciousness.
In the dreams I related before, subjectively I thought I was conscious. However, certain of my higher level brain functions still weren't operating as they should during that subjective experience of consciousness. With those aspects functioning and looking back at the experience (even that day) there were clear indications that I wasn't in fact completely conscious. So even what we do experience as consciousness (extended as the basis of idealism) is often, in and of itself, just misleading.