Does iCloud Photos support CR2/DNG raw?

I imported a folder of photos in Canon CR2 and DNG raw format into Photos.app. They show up fine locally in the app (I can edit them), but they don't upload to iCloud. Ordinary JPG files in the same folder upload successfully. The RAW images were shot without corresponding JPGs, ie the CR2 and DNG images are the only copy.

Are CR2/DNG unsupported by iCloud, or is there something wrong with my setup?

Solution 1:

I think it's working, I think it's still uploading them but the progress bar in Photos.app is missing. I looked at the total number of items visible at https://www.icloud.com/photos and the number is gradually going up. They're slower to appear on iPhone but I do see some RAW photos there, based on a random check.

The progress bar is now working and the "Uploading 445 items" counter is slowly going up instead of down, so it looks like it's slow to decide what it needs to upload. There's now only 6324 large RAW files left to upload.