@james Yes, I know very well that Repos is not managed by Cloudron, but whole process can interfere with Cloudron installations and be critical specially when configuring a new Cloudron in a case of disaster recovery or switching Cloudron instances with backup/recovery, or simply when installing a new Cloudron instance.
In fact, if repository cannot be reached, Cloudron cannot be installed.
Hetzner give a good guide on how to switch, and also their repository is always reachable, fast and stable.
How @robi suggested, it could be interesting to add to Cloudron install script some strings to avoid this kind of issue.
Could be a speedy mirror or ability to pass parameter in ./cloudron-setup eg. ./cloudron-setup -h or something where user can chose wich mirror to use. -h = Hetzner, and so on.
At this point, script will manage all the whole process and continue installation of packages and Cloudron instance.