I do not know of a way of doing this, and if there was one change I would love to see on the PX, it is this. All my other synths show me this. My workaround is to note the next program slot I am happy to overwrite before I start editing.
I'm sorry to get this posted after a recent update but this has always been a hard workaround:How will we know what Program we are going to overwrite with a newly edited Program, if (as at present)COMPARE (when Writing a new Program) doesn't SHOW the name of the Program we're about to overwrite?Thanks!