I don’t know if is a definitive list, but I know that Burly users have upgraded to Primo feet and have used the Primo core. Ryan mentions that some of the benefits of the new core are lost when using Burly trucks and a Primo core. The Z axis is also interchangeable as noted in this topic, and towards the bottom of the topic, one user was using the Burly Z axis on a Primo. The mounting plate is also interchangeable, though it usually a Primo user using the Burly mounting plate so that Burly spindle/router/laser mounts can be used on the Primo