Please consider reverse-proxying https://api.rubygems.org/api/v1/dependencies at /rubygems/api/v1/dependencies so that dependency lists are fetched through this API, instead of calculated locally, by downloading and parsing all gemspec.rz files.
For your reference, here is a Caddyfile that I use to test the feasibility of the reverse proxy:
localhost:8081
log stderr
proxy /rubygems https://mirrors.tuna.tsinghua.edu.cn {
except /rubygems/api
}
proxy /rubygems/api https://api.rubygems.org {
without /rubygems
}
(I am fully aware of the "we don't do reverse proxy" policy of this site, so this is only filed in the hope of being useful to all RubyGems mirror users)