How do I safely restore files to a shared folder after they were replaced with symlinks created by iCloud's "Optimize Storage" feature?

Question

(Thanks in advance for suggestions on how I could make my question clearer)

Context:
I have a team that uses a shared folder that we each auto-sync to our local machines. We use Google Drive and Google's Backup And Sync application to manage the syncing, but we could be using Box or Dropbox or any other cloud storage with auto-syncing.

Problem:
Some team members have had iCloud's "Optimize Mac Storage" feature enabled, which over the course of a couple of months has led to files in this shared folder being replaced with .icloud symlinks that don't work for anyone else on the team.
For example, let's assume shared-team-folder/ contains file1.pptx, file2.pptx, and file3.pdf.
At some point team member Bob's mac replaces syncs all three of those files to iCloud and replaces them with file1.pptx .icloud, file2.pptx .icloud, and file3.pdf .icloud placeholder files instead. Google Drive's Backup And Sync (or Box or Dropbox) shares Bob's changes to the cloud, which then get pulled down onto the computers of team members Alice and Carol.

Questions:

1. What procedure can I use to ensure that the files are safely restored back into the folder for all to use?
2. Will unchecking "Optimize Mac Storage" put the original files back?
3. If Alice, Bob, and Carol all have "Optimize Mac Storage" enabled, does the order in which they disable it matter?
4. Are there things we could do wrong in this process that could lead to the files being lost?

Answer 1

Yes, it's a pickle to have two competing cloud drive sync's running on the same files. You need to ensure that iCloud, Google, Dropbox, Box, etc. are not using the same locations.

iCloud sync's the Desktop and Documents folders so make sure none of the other competitor cloud drive sync folders are not located on the Mac desktop nor documents folders.

I would have the problematic user disable the Google sync and download the documents from iCloud then move them to a new folder outside the Desktop or Documents folders. Then ensure that the folder that Google uses to sync is also not in Desktop or Documents. Then enable the Google drive sync new location. Move the files into Google drive sync folder and let them sync back to Google. That should fix the problem once the other users sync them back down from Google.

If more than one user has turned on the iCloud Desktop & Documents sync feature they need to do the same thing. Except now someone has to figure out what's new versus old in regards to the files that have moved into individual iClouds over a period of time. So if that is the case, ouch... That's painful if it's a lot of files.

Decide on a single cloud solution and stick to it. Do not mix your cloud solutions. This sounds like an accident. So hopefully it was just one user who did this.

Check the Google drive that's on the Google Cloud see if the files were all replaced with .cloud links. If so then the master copy should be on that one users personal iCloud.

Once you've resolved the Google mess. Then the user can either continue to use iCloud or they can turn off the Optimize feature, download all their files (if they have enough local storage) and then they can turn off the iCloud Desktop & Documents feature if they really don't want to use it. Otherwise they need to keep other cloud systems outside the Desktop and Document folders.