Well I calculated it as follows.. If I want a 70vg juice, I need to keep my flavours below 20% in order to use 100% PG nic. If I want to use 50/50 nic, I need to keep the flavours below 25%.VG based nicotine kept in a cool dark place will outlast PG based nic stored in the sun.
Nicotine will degrade regardless of the carrier due to a number of variables rendering your rather terse comment moot in consumer sized quantities.
People should buy their nic in the carrier that suits their needs (and shaking endurance) best.
Now, in the olden days.. 20% wasn't THAT much. These days, it's a ton. I usually never go above 17-18%, so I can actually use 100% PG nic. Maybe I should order that on my next refill.