1st Question, no. CCA 3.0 does not support 's' button.
(CCA PM can give forward looking guidance)
Regarding extraneous ephone-DN Tags, this used to be the case prior to CCA 3.0.
A new config started out of the box with CCA 3.0 and the newest SWP doesnt auto ephone register anymore or reserve as it used to.
Upgrading to CCA 3.0 on an existing deployment should thrown a pop up from CCA asking you to allow CCA to turn this off, but it wont remove whats already there. Hopefully, going forward, you will notice an improvement here.