Ironically this is exactly how cloudflare handles its spam prevention. Have a dynamic IP? Its Russian roulette until cloudflare decides you're dangerous.
My favorite experience was building a website for a client, putting cloudflare in front of it, then discovering cloudflare blocked the IP of our client's office from seeing their own website.
My favorite experience was building a website for a client, putting cloudflare in front of it, then discovering cloudflare blocked the IP of our client's office from seeing their own website.