Neither is necessary. Just be sure to enter all the control channels for the system you are monitoring. The radio will switch over by itself. Be aware that if you have multiple sites, you must program those sites individually - don't lump them into one system. Unidens will latch onto the first control channel it finds and ignores anything else.
It is so much easier to download software like Freescan and use that to program your scanner. Manual programming of a trunked system is an ordeal. With you being a premium subscriber, you can download all the data needed to program your scanner.
There are several videos on how to use Freescan on Youtube.
