One wrinkle here is what happens when storing values in non-OBJECT!/MODULE!/LET!/etc.
e.g. what happens with BLOCK!.
>> block: [a b c]
>> block.2: 10
== 10
>> block
== ??? ; [a 10 c] or [a '10 c] or ...
The pretty obvious answer would be that this would not be a case where the substrate stores lifted values.
But then, do block.^2: 10 or block.^2 have any meaning at all?
If we considered items in blocks to have an "implicit lift" then they'd always be plain forms, and hence quoted, hence block.^2 would be the exact same thing as block.2.
But perhaps if out of range was considered to have an "implicit lift", block.^4 could give you back an out of range ERROR!, while block.4 would be a panic?
Or maybe block.^2: void would be legal for erasing elements, while block.2: void would not?
I'm not sure if restricting out-of-range behaviors to meta-indexing is beneficial or just a hassle to try and find some angle of consistency. But either way, this does spell the likely end of ideas like block.^2: append/ being a synonym for (unlift of) block.2: lift append/.
(Worth it, considering the benefits and that I can't think offhand of tons of great uses for that.)