As a running light it would simply augment what you already have for a tail light. That's a good thing though. When I rode my AK 550 home from the dealer I was riding with a buddy along the way for company. He followed me. I planned that.
He mentioned that the tail light on the AK was good by itself. This was before I added anything of course. But he also mentioned that the center 2 LED bars for the brake lights were bright but smaller than he would have wanted on his bike.
After I added a Knight Riderz LED tail/flashing brake light bar he followed me on my trip in May this year. He said that the tail light function of my added LED bar improved the tail light even better than it was. But the biggest difference was that the LED bar almost doubled the bright light of the brakes and made them a lot better than they were. That was in his words as he followed me (we were communicating via Sena BT headsets).
I don't know if the Shad LED bar is brighter than normal tail lights or as bright as the brake lights normally are. I also don't know if the Shad LED bar has dual mode running light and brake light (low intensity for running lights and high intensity for brakes). If your tail lights (running lights) are good then maybe you want a sudden added bright light bar that wasn't there until brakes are applied to catch attention.
Here is a link to a short video I made of my LED bar in action. The LED bar I added is below the stock tail light assembly. Maybe this will help with the decision.
https://photos.app.goo.gl/CJpzXXDgpJtQLB3EA