Our rails are full length and they feature boxed ends for the ability to support the vehicle anywhere along them. What I usually do is jack the car by the center tube portion and place jack stands under the boxed ends.
Another feature that is unique to BMR rails is the main tube is parallel to the ground when the vehicle is level, instead of sloped like the chassis it mounts to. Not a big deal, but something we wanted to do and knew the competition wouldn't offer (we released rails before anyone else)
All of that said....I don't use them. I removed them from my car and I use my CB005 to lift the rear, and up front I use a block of wood on the jack. If I was to lift the car more often, I would keep them on as they are much easier.
I've read that people install and remove the rails as needed for weight. Only a few bolts hold on each rail. I'm lazy I guess, I left mine on.Since you removed your BMR jack rails do you want to sell them?