The scanner only needs the currently active control channel to track the system. In normal circumstances, the control channel doesn't change. Occasionally it may switch to an alternate. Having the four CCs (in red) programmed should allow the radio to track the system properly almost all the time.
On the TSYS tab, with the newly created Palmetto P25 system highlighted, click in the talkgroup section of the page. From the Edit menu, select "insert new object". By default, the new talkgroup that is created will be a wildcard object. Name it and assign it to an appropriate scan list. This talkgroup will cause the scanner to allow active talkgroups that are not programmed to be heard, helping you to identify them. Once you do identify them, past them back here so they can be added to the database.