[BostonCard]

All in all (all and all)

I am not convinced this one hasn't been flipped.  [And I note I begin a grammar-related post with a double negative.]
I had been under the impression that this was a reference to the biblical phrase of God being in "all things in all places".

You are correct; they seem to have flipped the correct version and the eggcorn.  See here:

https://grammarist.com/usage/all-in-all/

The idiom meaning everything being taken into account is all in all, not all and all. All in all is an emphatically redundant variant of in all, which has roughly the same meaning. In fact, for writers who value concision, in all is a good replacement for all in all.

BC

[BostonCard]

All in all (all and all)

I am not convinced this one hasn't been flipped.  [And I note I begin a grammar-related post with a double negative.]
I had been under the impression that this was a reference to the biblical phrase of God being in "all things in all places".

You are correct; they seem to have flipped the correct version and the eggcorn.  See here:

https://grammarist.com/usage/all-in-all/

The idiom meaning everything being taken into account is all in all, not all and all. All in all is an emphatically redundant variant of in all, which has roughly the same meaning. In fact, for writers who value concision, in all is a good replacement for all in all.

BC