I am pushing out labels to my Mirror Server available for XML printing. I am trying to make my ZPL compatible with P4T, QLN420, ZT410s.
 
As I am doing this I have noticed that all of my formats contain the following ZPL before the actual field definitions:

Most of this ZPL is unrelated to the format but more related to the printer function.
 
I have some questions regarding ZPL commands?
 
* Do the above commands only affect the format that they are part of?
 
* Do commands such as ^MMx, ^MNx, ^MTx affect only the format they are part of or do they persist?
 
* If ^MMx, ^MNx, ^MTx  persist, do they persist printer reboots or is a ^JUS or some other command required for them to persist reboots?

Now onto XML printing:

Could I remove the above 13 ZPL lines from each of my formats and save as an individual format eg: GENERIC_SETTINGS.ZPL... and then being able to recall this as part of my label formats, like this:
(update: DFE should be XFE)

What are the best practices in situations like this?

thanks
/c