I sure hope your customers read this comment, they should know that you're likely to defraud them, since it's not "nice" of them to want you do what you agree to.
In the blog post your claim that "small businesses cannot depend on huge providers like google or cloudflare" may or may not be right, but it's absolutely not evidenced by you not reading the TOS.
I suppose you're also right that there's no way to monitor whether you would be considered an image proxy. I would appreciate more clarity on that myself.
It's extremely clear in your case though. You said it yourself, "all my subdomains that operate as image proxies are banned."
I don't understand your position, you called your own servers image proxies. So how could you not know they were image proxies?