Please don't add it at the moment. I am its author and decided to not include it in OPM since it contains an issue leading to potential loss of meta data.
fpExif and dExif are different things. dExif was one of the first libraries to access EXIF metadata. However, it is badly written and has many issues. Therefore I decided some time ago to rewrite it in a "better" way.
The issue mentioned above is also present in dexif. The problem is that EXIF is a binary structure, data often are referred to by their offsets relative to a marker in the file (TIFF header). There is one particular EXIF record "MakerNote" which manufacturers can fill with additional data in an arbitrary and undocumented way. Usually they use the same structure as the rest of the EXIF segment and refer their file offsets to the TIFF marker rather than to the start of the MakerNote tag. Now, when a user of fpExif or dExif edits an EXIF tag in a way that the binary data are shifted within the file the MakerNotes are destroyed because their offsets are not corrected (because it is not documented).