Why does the E-Ray cycle the electric motor when cruise control is on?

Curious to see if anyone knows the answer.

I was using cruise control for a bit in touring mode and noticed the electric motor was active and draining the battery. After a while the electric motor went into regen mode and the engine was pushing harder to compensate. It seems like it will keep cycling like this.

After a bit of searching it seems like one answer is that it uses the electric motor so the engine can be in v4 mode for longer for efficiency.

But it seems like putting wear on the tires, battery, and the inefficiency of charging the battery would be a detriment.