Today’s Question: Does XMP include edits in the Development module [in Lightroom Classic or via Adobe Camera Raw]?
Tim’s Quick Answer: Yes, when XMP files are saved for raw captures edited with Adobe Camera Raw or Adobe Lightroom Classic, along with standard metadata values the adjustments themselves are preserved.
More Detail: When you edit a raw capture using Adobe Camera Raw, or with Lightroom Classic if you have enabled the option to automatically write metadata updates to the source image files, standard metadata values are saved to XMP “sidecar” files alongside the original raw captures. That metadata includes standard fields such as keywords and star ratings, for example.
In the context of Lightroom Classic, that saved metadata does not include features that are specific to Lightroom Classic. Metadata based on those features, such as pick/reject flags, collections, and virtual copies, are not included in the metadata saved to the source images. Instead, that information is only contained within the Lightroom Classic catalog.
Interestingly, however, the adjustments you have applied in the Develop module in Lightroom Classic (or using Adobe Camera Raw) are saved in the metadata for the source image. That means that, for example, if you had lost your Lightroom Classic catalog, the standard metadata and Develop adjustments would still be available simply by importing the original photos into a new catalog.
In Lightroom Classic the option to automatically save metadata to the source image files is turned off by default. However, you can enable this option by turning on the “Automatically write changes into XMP” checkbox on the Metadata tab of the Catalog Settings dialog in Lightroom Classic. That dialog can be found by choosing “Catalog Settings” from the Edit menu on Windows or the Lightroom Classic menu on Macintosh.