Hosting sites like Kinsta send a nofollow in the header. I think they use this: developers.google.com/search/reference/robots_meta_tag
It would prevent search engines from indexing temporary domains and allow us to use them as staging sites for clients.
So we are using Cloudflare for the ploi.link domain and it seems it is not possible send along custom headers. So what we did, is actually add a firewall rule to block bots.
With that I consider the feature request to be solved.