We have found a solution together with @as9136 that will likely provide sufficient protection for IPv4 users, and we have a good idea how a long-term setup can look like (but it will take a while to get there). Thanks a lot for all the networking and support!
The switch is awaiting DNS propagation (pending for > 30 minutes already, and might take another hour for some users. And indeed, we are not happy with the service quality of #namesilo).