Using [XDataExcludeProperty] makes PUT set NULL to excluded properties.
IMO, a more correct behavior would be to exclude the property from the UPDATE sql
Guess once you use [XDataExcludeProperty] you have to use PATCH always, unless you can set the value to the excluded fields from other included properties.
I guess by using a Middleware one can enforce the use of PATCH only methods to modify entities.
Regards,