The whole reason I made the modemst backup scripts is because I was experimenting a lot with radio / ril settings for my version of CM10, trying to get 4G working and stuff.
At some point I did something that killed my radio, my PRL was not showing, baseband said unknown, could not make calls, nothing.
I did the Sammy unbrick a few times, wipe setting, could not get it working at all.
I always dump all the partitions of phones that I mess with before I start messing with them, and I had found that restoring the 2 modemst partitions fixed my problem, and radio started working again
So I said to myself, if people are going to be installing my CM10 and messing with things to try to get 4G working, they should probably be backing up these 2 partitions, just in case they mess up something the way I did, so I made the script.
I think these 2 partitions contain the PRL and NAM programming stuff
Anyway, it is just an option