To avoid any & all confusion related to contents of user-created partial presets (including mine, as reported above) - this bug/fault can be confirmed using DxO-supplied presets.
Set-up an image with Distortion / Constrain to Image set as; 
(Unconstrained )
-
and then apply either one of DxO’s 3 - Neutral Colors OR 4 - Black & White presets
-
the result for Distortion / Constrain to Image will become
(Constrained)
– despite neither of those presets containing any setting whatsoever for Constrain to Image … which, internally, within the sidecar/.dop file, is defined via:DistortionAnamorphosisKeepEntireImage
Note: Testing by Platypus confirms that this same (faulty) behaviour does NOT exist for the Mac version - It seems to be an issue specific to the Win-version.