v1.21.1, v0.21.0, v0.19.50

So, when you load an old-style schematic file, like the one below which is my test file:
engine.zip
it ought to honor the origin in the schematic, given by the WEOriginX/WEOriginY/WEOriginZ tags in the NBT.
But it doesn't, and instead puts the origin at the lower corner of the object's bounding box.

Okay so looking at this more, apparently there's 2 sets of tags, the WEOrigin(X/Y/Z) and WEOffset(X/Y/Z) tags, that, I found a thing that says

WEOffsetX: Integer, Player offset [X] relative to schematic origin, where the player created the schematic
WEOffsetY: Integer, Player offset [Y] relative to schematic origin, where the player created the schematic
WEOffsetZ: Integer, Player offset [Z] relative to schematic origin, where the player created the schematic

WEOriginX: Integer, offset [X] from map origin to schematic origin
WEOriginY: Integer, offset [Y] from map origin to schematic origin
WEOriginZ: Integer, offset [Z] from map origin to schematic origin

and, not having looked at this much more, I don't know what this means exactly. I think this is saying that WEOffset is the actual origin, instead of WEOrigin, which, well that's confusing, but idk.

For the record, this file was generated by an old version of WorldEdit, for 1.2.5.

Did the same happen in older versions of litematica, such as 1.20.4 ?

Litematica has thus far never read the origin from .schematic files. The .schematic files that I originally used for testing and development were all from either Schematica or MCEdit, and neither of those write an origin to the file. Until now I had never even thought about this...