frequency template for 450b and 450 SMs

I want to make a template I can use for all of my SMs that will select all of the channels available to scan. If I make a file that selects all of the channels available on a 450b, it won't do anything on the older radios that wont' support 5.1/5.2. is there a way to apply a template that ADDS channels to the radio, instead of replacing? or a way to apply c to a radio, and have it just ignore the channels it doesnt' support (while selecting the ones it does)?

What I do is have a seperate file for 450b's and 450's, if the radio doesnt support the channel it cannot be added into it as it wasn't programmed to do so, however you can have two seperate files for each that scan select every channel available that it can see, so for 450's everything above 5.1/5.2 and for the 450b's everything from 4.9 to 5.9 depending on your region. Once you have those, apply them using Configuration/Unit Settings/Upload and apply configuration. Let me know if this helps.