@wmatioli Yes the answer is- "enable the option to treat JPEGs as separate files". then-
1) If you only have RAWs in the library currently, You can import the JPGs to make them visible beside the RAW image by doing a [Synchronize Folder] action. Future imports of new camera card files will add both RAW & JPG to the catalog as separate files.
2) Then view both selected images (RAW & JPG) side-by-side with [Survey View] (Keyboard [N] ) in the Library Grid mode,
3) Or in the Develop module use [Reference View] MENU > View> Open in Reference view. Here you can develop one image while looking at the other for visual comparison as you edit.
"is there a way to ensure that those chosen JPGs gets synced to the cloud?"
Photos that can be synced to the Lightroom Cloud can be of any file-type in the catalog library. RAW , JPG, , TIF or PSD.
The important fact to note is that whatever image you add to a synced Collection, Lr-Classic only sends a proxy (smart Preview) file (as a DNG) to the cloud, so file-type is un-important for syncing from Lr-Classic.
Over-writing files is not good practice. You are better to leave all original files untouched (as Lightroom intends) and use the Export function when you want a JPG that has all your edits 'burned into' the new JPG image. With the edits preserved in the Catalog you can export JPGs at any time in the future with the same, or new, edits without destroying your original files. Remember EVERY TIME you 'Re-Save' a JPG file it uses compression to change the pixels for a smaller sized file. ie. 'Saving' JPG to JPG is ALWAYS destructive. 'Exporting' to JPG in the catalog will only ever be one compression for any new JPG.
Deleting files, well that's your decision, but IMO the RAW file is the one to keep.
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