I'm assuming the simple answer is yes, the run scribe efficiency metrics will be lower.
But like most things with running, I'm also assuming it's far more complicated than it initially appears.
Here's a hypothetical scenario:
Two identical runners with the same gait etc., complete the same 5k race with the exact same finish times. Runner A goes the same pace the whole time, while Runner B uses an "interval approach" (go hard, recover, hard . . . or the Galloway run-walk-run). Wouldn't runner A likely have more "air time" over the course of the race, and thus higher efficiency metrics than Runner B?
Even if Runner B "race walks" during the recovery periods at a relatively fast walking pace, the higher ground contact time while walking would translate into less "efficiency" in the sense that this would reduce the overall time Runner B spent in the air while covering the 5k distance and thus the efficiency.
This is why it I imagine that it would feel much harder ( and much less efficient) to walk a 5k in under 30 minutes as opposed to running it. And this is why elites have such high flight ratios, e.g. see their post on Elites vs. Mortals: because it maximizes their efficiency.
And perhaps this also gets into that old debate about why you don't see elite marathoners running their PRs with an interval tactic. It's more efficient if they just stick to a mostly consistent pace with slightly negative splits (and mostly consistent "air time") than not.