The only RWZ graphics files we know about comes from Rawzor, which is a proprietary lossless image compression software which compresses camera raw images without any loss in image quality or meta-information.
It does not make much sense to convert standard JPEG pictures, although it's not impossible task with photo editors that support saving to RWZ format. But to preserver all metadata it's best to export the original source RAW file and not the already compressed JPEG image. So while yes, jpg to rwz conversion is indeed possible, but subpar choice for RWZ export.
Updated: January 9, 2024