Two things:
2/ Stability: My rig (5x 1080) is crashing several times a day with Nemosminer. I'm talking once an hour on avg. That's not good. On single coin it chugs along perfectly fine without reboots. I haven't yet been able to pinpoint the issue, so I can only *guess* either one instance of ccminer is unstable or the switching causes it.
Maybe your crashing issue arises with a certain algorithm that you do not ordinarily mine, or a certain version of CCminer that you do not ordinarily use. CCminer SP-Mod doesn't work at all on my machines, so I've disabled it.