Comment by xp84

Apple will allow you to have multiple Apple IDs tied to the same phone number -- my kids' ones have my number on them. So for some purposes it seems fine to just reuse the phone number for a second account -- like for your kids, or for a "sandbox" account to use testing your app so that you don't have to use your real iCloud account.

However, for your purpose of avoiding Apple's capricious BS, I probably wouldn't go that route since if their braindead fraud systems or braindead employees decide you're a threat actor they could definitely default to "Ban account. Find all their evil backup accounts that have the same phone numbers or contact emails and ban them too."