Four on the Floor or keep trying for the good ol' 2020?

I originally taught the four on the floor contact to both my border collies. Mainly I did that with the Aframe because I wanted to figure out a way to be easier on Breeze's body because of her hip dysplasia. Lizzie loved the four on the floor but figured out how to jump over both the up and the down contact....so I had to retrain the 2o2o, which proved way harder then I thought. So Breeze has been doing pretty good with the four on the floor on the Aframe but I would like to have a 2o2o on the dog walk so she is controlling her speed and being a little more careful on the dog walk after a few accidents she has had. Well, I started with a lot of working on a small plank, I shaped her being in a down position with her two front feet off, and if we hop on and off the board she loves the 2o2o, and I had thought it would be an easy retrain. I am finding every time I add in any excitement we are back to the four on the floor, so I am trying to decide just how much I want to fight this battle, do I just work on the four on the floor and be happy or do I keep going and insist on the 2o2o on the dog walk? I know I can eventually get a 2o2o, I think...but how much time is it worth?? I already know I am leaving the Aframe as is, she doesn't position herself forward even though she anticipates the jump and the reward appears that way, so I might try to work on that but otherwise I am pretty happy with the aframe.