Well, I'm doing much the same as you. I'm just sharing this expression because I think
[Album Artist (auto)]
and
[Album (auto)]
is a good/similar idea.
I can get the hierarchy to be very consistent, in a folder naming structure,
AND in a view scheme, by using
a) for view schemes:
[Album Artist (auto)]/
If(IsEmpty([Album Mix]), [Album], [Album Mix])
b) for a directory naming template rule:
[Album Artist (auto)]\
If(IsEqual([Album Mix], Unknown Album Mix, 1), [Album], [Album Mix])
It's much better than any of these
[Artist]/[Album]
[Album Artist]/[Album]
[Album Artist (auto)]/[Album]
For example, I can enter "Various Artists" or a DJ/Producer into the [Album Artist] field, leaving the tracks properly credited with [Artist], as you say. This is the whole idea of [Album Artist (auto)] I would guess, so I'm just using it the same way you do, I think. It seems to be what it's designed for.
But the nice thing about the extra expression I've described above, is that it also handles, say, "World Fusion Mix" as an [Album Mix], overriding [Album], but leaves the original [Album] tag. This enables the track info to show the original album (and function with artwork and lyric lookups) but keeps the albums and tracks organized consistently, including any custom [Album Mix] albums I make.
Anyway, I'm just sharing a solution that's a similar concept to [Album Artist (auto)] and seems to make a nice partner for it, for Album names.
As for requests, yes it would be nice to be able to put expressions in fields, so I can make the expression into a custom field and call it [Album (auto)]. Or have it as a built-in MC field.