How to change the primary Baro and/or use lane affinity

Hello all, I have been looking at my logs and BAR0 is much noisier that BAR2 and BAR3. I presume BAR0 is the default used barometer and if so how do I change the primary barometer to one of the others. I see that EKF3 uses lanes and that these can apparently be configured but after a search I can’t find out how this is done. Any pointers would be much appreciated. Thank you.