I don't know if a re-usable Electron will ever make sense, but it's an interesting engineering problem to think about.

As lithium-ion batteries improve the potential mass fraction for each Electron stage gets better: lighter batteries mean more propellant. In a decade (maybe sooner) it might become feasible for the first stage to retain enough propellant for a propulsive landing like the Falcon 9. And in this case I think there's a big pay-off with the electric pumps: there's no need for a hoverslam, since the engines should be able to deep throttle to an extreme degree that's not practical with conventional rocket engines.

In a shorter time-frame the Electron first stage, because it is so small, is probably air-recoverable using the same approach that ULA is considering for recovering Vulcan engines.