If you don’t understand why it’ss broken, I guess that’s on you. If you’re to tbe point op is in terms of their needs, network topology etc and you still don’t understand the fundamentals, what do you expect me to say to resolve that? If you’re OK with supporting your broken, incorrectly configured network, then by all means. If you are not, then expect the answer from those you’re asking for help from to be “fix your shit”. Do not expect anyone to educate you. It’s like arguing with creationists - you picked this dumbass thing to get behind, I’m not on the hook to explain basic logic to you.

If you’re using double NAT, you’re doing something wrong. If you want to do it right, stop using double nat. If that doesn’t matter to you, and you’re comfortable supporting a broken-by-design network, do it.