- We don't currently support extensions (like "Largefiles" or "LockExtension") for hosted repositories.
- You can try enabling them them in the global `.hgrc` anyway, which may or may not work (or may work, but create security/policy problems).
- Proper support requires us to evaluate the capabilities each extension provides on an extension-by-extension basis and make sure that relevant rules and policies aren't being violated. We can't do this easily in the general case.
- This is a very low priority because there isn't much interest in any specific extension.