(Personal Disclaimer in case this question is obvious/stupid)
I had a rough experience with creating a Community and an unexpected redirect (in Production) and Support with Salesforce went on for two weeks with NO valuable feedback or information, so I want to avoid anything unexpected/irreversible since I can't rely on support.
Furthermore, custom Domains need to be done in Production, as they are not supported in dev orgs, which is another reason why I need to be sure of what my impacts are before proceeding
So! Domains >> New Domain >> I have a CNAME set up and all that jazz, I just need to hit save and activate. This doesn't automatically change the URL for my communities, right? That would be done manually? Sorry if this is a dumb question, I'm just very skeptic of Salesforce with Domains from the last 2 weeks on the struggle bus. I want to confirm that nothing will automatically happen just by creating this domain.
Bonus question... if I assign this Domain to a Site using Custom URLs, this too does not change any other communities/site URLs, right?