OP....I know you've already placed your order but thought I would at least let you see my thread. If you're going to be installing these yourself just know what you'll be getting into with that style of insert. If you drop the cradle all together you can probably get a decent angle on those inserts but if you plan to do it from side to side there is a good chance you'll run into the issues I did. Not saying you will 100%. Just know how much easier the Pedders inserts are to install.
Mine were Energy Suspension inserts. I don't know if the poly will be the same as BMR but the design is the same. IMO it was worth the extra money for the Pedders inserts.