I mean, in some sense, Cloudflare simply accepts the security posture of "already lost", right? They run workloads for multiple users within the same process separated by nothing more than V8 boundaries, which even Chrome (which always claimed to run tabs in separate processes but actually didn't due to various edge cases) finally stopped doing (now afaik they do fence origins within processes) as it was so risky... Cloudflare's best lines of defense past "we patch often" are merely that they sort of KYC at least most of their users so they can log everything they run with their identity and that they take users of similar trust levels (age of account, level of KYC, amount of usage, etc.) and group those into processes... but, at the end of the day, they rely on something that I would certainly never consider reasonable to ship in production.