Hi Jeremy,

Depends on exactly what you want to do, and what level of persistence you want your content to have.
I will assume at this point that you do not want to use MSP at all, you just have an MSP Package (APF) and want to install it by pushing it from a PC via adb.
MSP Packages are generally used in Android to install APK's - so if you "extract" an APK from an MSP Package (which can be done with the MSP Package Builder)...
Then you could use the adb "install" command just as you would with any APK. If the MSP Package includes any other files besides the APK, you MAY be able to use adb "push" command to put them on the Android device -- as long as they belong in a folder to which you have write access through adb.

One thing you would lose by not installing files via MSP or SOTI  would be that that the APKs you install via adb will NOT persist over an Enterprise Reset.  An Enterprise Reset allows applications installed by privileged agents to persist, while anything not installed by such an agent is removed - thus providing a way to bring a unit back to a "known good state" defined by the Enterprise administrators, and preventing the need for devices to be "brought back in" for cleanup, in the event the user is able to install unwanted applications or settings.