Small update...
I sent Scott some additional logs from Stock yesterday on the PRL and Profile update process, hopefully that will lead to a breakthrough with adding the options to AOSP. I've actually flashed back to the 5/28 nightly from
https://docs.google.com/file/d/0B2TG...p=docslist_api, it works great and LTE is preserved after a reboot.
Boot to recovery
Backup
Factory Reset
Wipe System
Reboot to recovery (don't install SU)
Flash TW ROM
Boot to System
Validate LTE connectivity (if no LTE, then do a Hands Free Activation)
GPS Lock
Flash PRL (if you use a custom PRL, HFA gets the current Sprint PRL with no SMR)
Reboot to recovery
Factory Reset
Wipe System
Reboot to recovery (don't install SU)
Flash 5/28 and GApps
If you lost any key data, extract it from your backup.
Profit!!!