[cup-of-tea]

While interesting, a yak shave is where you go off on a long excursion to solve a problem that helps you solve the real problem. This, on the other hand, is just having a hobby. Calling it yak shaving doesn't seem appropriate.

[octorian]

The long excursion might be seen as implementing all that code to do EFS-to-TAR. (Rather than figure out how to compile a Linux kernel module, or run an old version of Linux on something.)

If I was trying to do this project, I'd just do what it took to get an EFS-supporting OS up and running, expose via NFS, and be done with it.

[ucsdrake]

You must be fun at parties.