One can make it also easier when switching profiles: They can just add a link to their new account. The profile info will be cached on other servers, even when the origin server goes down, providing a proof of the accounts validity. Of course lemmy could simply add a validation url similar to mastodon does and that would make this moot.
Blocking whole regions sounds like overkill. Just block the alibaba subnets. We do the same on our end. If you want I can provide you the cidr ranges.