Lock inverse crop selection ratio (landscape <-> portrait)

When an image is in portrait format, locking the crop selection ratio at “3:2” means height:width=3:2.
When the image is in landscape format, the same setting means width:height=3:2.
In most cases this meets expectations and is practical.
In some cases, however, I would like to crop a portrait out of a landscape, or vice versa. Is there a way to lock the selection ratio at “2:3” instead of “3:2”?