That is really unfortunate. I don’t even know what to suggest in that case…
As a long-term goal, we do want to set up website mirrors, particularly one in the EU. I have discussed occasionally with @carandraug, who I believe has an internal mirror of the ImageJ & Fiji update sites, but nothing public yet. If anyone else has motivation to push on the issue, that would be helpful.
Interesting idea—but of course it requires community members willing to keep active seeds going, and keep them current with the newest version every time.
I think it will ultimately be best for the ImageJ Updater to select the best/fastest mirror somehow. Maybe it can be done automatically on the server side from the base URL. But we don’t have the infrastructure or bandwidth to explore that at the moment.