Emily, would you be able to take this on?

Sure.  Are there outsanding issues where these can't be turned back on or is it just a CL to re-enable them?

I think the biggest concern here would be runtime.

This bug is obsolete. The benchmark smoke test is already reenabled on Nexus 5X. They are not enabled on Nexus 5 though due to stability issue (the suite keeps being flaky there for some reason :-/)