Same setup as the OP but an older CRV and a gas coach. The only problems I have had with the bar were self induced and quickly corrected. Quick and easy setup and very reliable.
With a downhill run I'll get an indication of the brake application only if I am on the coach brakes or a quick flash when I down downshift the transmission. No braking action when the coach is holding a steady or slow speed reduction such as coasting to a stop light. About the only time I see the brake indication on the CRV is when I'm actively braking the coach. The bar has a heavy spring that first must be overcome before the system becomes effective. Slow speed reductions is not enough momentum to activate the system.
Rather than using the braking action switch built into the bar I wired the dash indicator into the brake light switch at the CRV brake pedal. The connection point is before the tail light diodes so the dash indicator lights with the CRV brake lights rather than when the tow bar is active. Brake light signal from the coach to the CRV lights does not light the indicator.
Brake cable routing was simple. The bumper end is just below the front licence plate so I tuck the loop behind the plate when not in use. From there I routed the cable along the left side of the engine compartment under the battery and other such to a spot at the fire wall below the steering shaft. Plenty of room for the bends.
With everything connected and the towbar arms locked the cable from the bar to the toad should have a bit of slack. You don't want guitar string tight. Easy slack setup is when the arms are unlock and fully compressed you should have just enough slack to disconnect the bar cable from the toad.
For more info they have a YouTube video detailing installation on a 2014 CRV. Click
HERE to view.