It would be useful to add an "lfs open [--ifcomp=<component_id>] [--ofcomp=<component_id>] <command>" that opens the stdin and/or stdout with the specified component ID values, so that e.g. "dd" could be used as a resync tool for stale components, or other arbitrary commands (e.g. MPI file utils for parallel resync, HSM tools for archive handling, etc).
Also useful would be to open a specific mirror number for whole-file access, instead of just a single component. That would be something like "--ifrepl=" and "--ofrepl=" options.