9
I'd suggest don't
I don't think you have to configure anything special but I could be wrong about the Slack.
I never did anything special for it but I have users running Windows and they frequently use spaces (yuck) in the file names when they store to the server via Samba. No problem.
What happens when you try? If you're viewing a file list from something that shows exactly how it is stored vs something that masks reality from the user (Windows) it might appear strange.
Even on Windows the spaces and long names are stored differently than what you might see in a file manager. But it does work.