[Moto E4 Guides, News, & Discussion] ALI12:
Hi, well, I have downgraded these partitions already without any problems. You can downgrade devcfg(device configuration partition) without any probelms. downgrade won't brick the phone but if you flash other carrier device configuration, it will brick phone :) as long as you flash Sprint to Sprint, it is OK and even downgrade to older build. Only partition that will hard brick your phone in E4 is SBL1, if we downgrade this partition then we get qualcomm 9008 and it can be repaired as well, anyway...

Logs with bootloader BB.32 and flashing_unlocked/bootloader unlocked:

C:\adb>fastboot getvar version-bootloader
version-bootloader: moto-msm8920-BB.32

C:\adb>fastboot getvar sbl1.git
sbl1.git: git=MBM-NG-VBB.32-0-gfe9cf09

C:\adb>fastboot getvar tz.git
tz.git: git=99b0ebd-dirty

C:\adb>fastboot getvar devcfg.git
devcfg.git: git=99b0ebd-dirty

C:\adb>fastboot getvar keymaster.git
keymaster.git: git=99b0ebd-dirty

C:\adb>fastboot getvar cmnlib.git
cmnlib.git: git=99b0ebd-dirty

C:\adb>fastboot getvar cmnlib64.git
cmnlib64.git: git=99b0ebd-dirty

C:\adb>fastboot getvar prov.git
prov.git: git=99b0ebd-dirty

C:\adb>fastboot getvar aboot.git
aboot.git: git=MBM-NG-VBB.32-0-g91d91c6

downgrading bootloader partitions:

C:\adb>fastboot flash cmnlib cmnlib.mbn
sending 'cmnlib' (251 KB)... OKAY
writing 'cmnlib'... OKAY

C:\adb>fastboot flash cmnlib64 cmnlib64.mbn
sending 'cmnlib64' (251 KB)... OKAY
writing 'cmnlib64'... OKAY

C:\adb>fastboot flash devcfg devcfg.mbn
sending 'devcfg' (128 KB)... OKAY
writing 'devcfg'... OKAY

C:\adb>fastboot flash aboot aboot.mbn
sending 'aboot' (1536 KB)... OKAY
writing 'aboot'... OKAY

C:\adb>fastboot flash keymaster keymaster.mbn
sending 'keymaster' (251 KB)... OKAY
writing 'keymaster'... OKAY

C:\adb>fastboot flash prov prov.mbn
sending 'prov' (187 KB)... OKAY
writing 'prov'... OKAY

C:\adb>fastboot flash rpm rpm.mbn
sending 'rpm' (256 KB)... OKAY
writing 'rpm'... OKAY

C:\adb>fastboot flash tz tz.mbn
sending 'tz' (1792 KB)... OKAY
writing 'tz'... OKAY

C:\adb>fastboot reboot-bootloader
rebooting into bootloader... OKAY

logs after downgrade... Yeah, BB.23:

INFOversion-bootloader: moto-msm8920-BB.23(*)
INFOsbl1.git: git=MBM-NG-VBB.32-0-gfe9cf09
INFOrpm.git: git=MBM-NG-VBB.23-0-gc6ac81e
INFOtz.git: git=MBM-NG-VBB.23-0-g82f94af
INFOdevcfg.git: git=MBM-NG-VBB.23-0-g82f94af
INFOkeymaster.git: git=MBM-NG-VBB.23-0-g82f94af
INFOcmnlib.git: git=MBM-NG-VBB.23-0-g82f94af
INFOcmnlib64.git: git=MBM-NG-VBB.23-0-g82f94af
INFOprov.git: git=MBM-NG-VBB.23-0-g82f94af
INFOaboot.git: git=MBM-NG-VBB.23-0-g87d0ac5

This radio problem seems to me has to do with either persist, oem and/or modem/fsg.

Persist - can read/write with adb shell root since it is blocked by aboot for fastboot flashing.

fsg/modem - as we all know can be flashed on fastboot mode doesn't matter bootloader locked or unlocked.

oem - can be flashed on fastboot mode (if downgrade - requires unlocked bootloader, if writing same version can be flashed on locked too).

P.S. count me in too with this Motorola sprint bug :)

---------- Post added at 11:48 AM ---------- Previous post was at 11:39 AM ----------

@ozmage: before flashing another phone's persist, make a backup of it...

persist contains dhob.bin, shob.bin and dhob.bin.bak/datablock which contains IMEI and other calibration data.