Additional high level brake light

[JTL]

I'm looking to add the SHAD high level brake light to my XR, looking at the rear light it's an LED set up.  Some research tells me that the light's intensity for tail and brake light operations is controlled by PWM (Pulse Width Modulation).  The SHAD light is LED and I was wondering if I can just splice the addition light in parallel with the existing brake and tail light?  Has anyone added additional an brake light?  Any advice or links would be appreciated. 

Thanks

[Watshot]

I wired in a Givi top box with additional LED tail and brake lights. Had to modify the Givi system as they don't do the rack connection for the XR. I'm not familiar with the Shad set up.

However, I had to install a Skene IQ-260 controller to overcome CanBus issues. It will likely throw a lamp error if you splice into the tail light (like mine did, I tried it first) due to the system sensing more current on the wire than is expected. The controller is tiny and easily tucks away under the seat and is easy to wire in (full instructions come with it). Cost me 98 U.S Dollars a couple of years ago, 33 of which was shipping. So about 75 quid all in.

It's available in the U.K through the "Adventure Bike Shop", but there was a delay at the time I wanted it and of course being the U.K; it was more expensive, so I ordered direct from Skene in the U.S. 

[JTL]

Thanks for the information  @Watshot, that will save me a lot of messing about testing it.