im running srx3.0 and am updated to ne4 bootloader and modem. could I use the flashable nj1 modem and bootloader zip to update the bootloader and modem only?
Yes, you can use the combo zip to update just the BL & MDM. I actually went from MJB incrementally to NE4, then NJ1 & finally the latest NJ2. My LTE has been solid since updating to NJ2. Less call drops with NJ2 than NJ1. I'm sure you know, but incase you dont I'll say it. You can update BL & MDM, but you can't downgrade. You can't skip versions either.