Based on my research, currently, we are able to exclude specific kinds of files from being uploaded, but there’re no registry or GPO setting to exclude specific folders to be synced to OneDrive.
Here is a similar thread on UserVoice forum, "Reassess the possibility to ignore or exclude selected OneDrive folders and files from the sync process". OneDrive PM Manager replied that related team are looking to expanding it to folders in the future.
Thanks for your understanding.
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