I didn't really make this clear in the intro video, but with the GPS+ panel you can map the left-most rotary control to one of your radios, including the active/standby switch button. Of course you get this in spades if you have a GNS530 or GNS430 GPS, whether it's a real one such as the Reality-XP or Mindstar packages or a fake one like those you will find in the Twin Otter Extended, Carenado Cessna 337 or Carenado F33A Bonanza (and no doubt other aircraft I don't have). With this GPS the COM1 and NAV1 active and standby frequencies are displayed on the GPS screen and you can toggle between them to adjust with the rotary control.
However, you can also get this full functionality in any aircraft using the LINDA functions I have supplied - including a toggle to swap between the NAV1 and COM1 radios. The only thing you lose is the visible indication of which radio is active, as this is normally on the GPS display. To compensate, I have supplied a variation of the 'toggle' function that briefly displays a message ('Adjusting/COM1' or 'Adjusting/NAV1') in a small window at the top of the screen when it is called. It's kind of like getting a Saitek radio panel free with your GPS! (Okay, only kind of )