Well, sad to report cejay's solution is more than likely just a fluke. Nothing force closes on my device when done as suggested. the only odd thing that happened was trying to place a phone call in lte only mode, the phone app stayed "on" even after the call ended, effectively blocking the data connection. Of course, killing it from the task manager(strangely it was listed as com.android.hidddenmenu) resumed everything back to normal, i.e lte only mode. As far as battery life is concerned, with cdma only mode, theoretical discharging curves put the life expectancy at slightly more than two days with no to lite usage, and over a day with moderate usage, including texting. That's definitely more than even the lte functionality test toggle can give.