Is it possible to read an exr with an oversized data window and have the image plane created read the entire data window with an appropriate layer transform? When I read an image rendered with overscan, the over-scanned data window appears to be discarded.

There is a bug with 21 with overscan not being properly handled. This was a regression from 20.5, as Copernicus has the whole data window/display window specifically to handle this.

Just came to ask same question

Thanks! will keep an eye on the bugfix!

I just saw this topic today.
I filed a bug report for this last year, I think, and they said it'd be corrected on H22.