Ok so I am new on here, I have never flashed mifi's before but here is what I have and where I am. I live in Eastern KY. My Local carrier is Appalachian Wireless (Part of VZW Rural America Partner) I have a jetpack 4620l that is supposed to be vzw prepaid, It will not however not connect to the local network which is showing as prepaid roaming partner, I also have 3 Sprint Mifi 4082's one of which I would like to flash to freedom pop (replacing my Overdrive) One to boost mobile, and one on Appalachian or vzw I don't care weather it is the 4082 or the 4620L prepaid. I know App has advance pay and post pay plans for phones so could I use data from mifi and calls and text from the doner phone as long I kept the data off? I thank you for you time and hope to hear back from you, I am just learning about flashing mifi's but have been an xda member for some time and rooted many devices, any assistance is appreciated... I may add this as a advance pay device to my account 5GB data for 29.95 plus calling plan if I go that route I would need the doner for calls. Also for the FreedomPop I would be using the OverDrive has the doner

FreedomPop is a mvno for Sprint and ClearWire - My device with them is a Sierra OverDrive
Appalachian Wireless is a local Eastern Kentucky CDMA provider 4G LTE VZW Rural America Partner