if you want to try not wiping data
you could flash
2.3.4/5.5.959 xml recovery file with
rsd lite then take updates
but if phone bootloops, after flashing xml file, you will need to wipe data
if you are not worried about user data
flash 2.3.4/5.6.890 xml, with rsd lite and take 2.3.4/5.7.906 update
or
flash
2.3.4/5.7.906 xml with rsd lite
phone needs to be in AP Fastboot to use rsd lite
When the phone is off, press m+power and scroll down to AP Fastboot.
I would just wipe data in android recovery
and flash 906 xml
also phone will be unrooted during flashing
doogald may have other suggestions