No RocketLoader: Note that as of above tests with curl and wget, which do not interpret any syntax, hence do not load any JavaScript or styles or anything else, the problem is that the download of the raw HTML document always hangs.
Cloudflare cache is not active for the forum, the raw HTML documents were never cached anyway.
No VPS-specific rules. Generally not rules for the forum, aside of to bypass cache. The issue appears in both cases, so cache isn’t the issue either.