I am facing this issue right now. I need to create a separate developer account because I am risk averse. Do I need a new phone number for this? Online some people say yes, others say no. I tried creating the account several times but it just doesn't work. At this point I am planning to just get a prepaid SIM card from US Mobile for the phone number.
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."
I set up a couple developer accounts recently for my clients. Just use a new Google Voice number for 2FA. I had to live chat with Apple support to get past initial verification both times and after that setup went fine.
