Based on previous experience with other electronics, any time you add -communication- with other devices to a product, you can expect higher power consumption. I assume that that principle is what delayed adding cell phone communication to the mix; until the development of low energy bluetooth, the power draw must have been prohibitive; now, with BTLE, it becomes possible but not without at least -some- additional power consumption, which I would guess might account for the need for more frequent battery replacement in the new KS8s.
Even with my older model HAs, I have to change the batteries much more frequently when I use my mike clips with them.