I would think that even if they did rise, if you're on a sliding scale, this should be able to be countered relatively easily. With some deductive logic, between meals when you're stable and aren't on an upward or downward trend, you should be able to
vape 1ml no nic, watch the trend and figure out how you need to adjust for that mil.
Now obviously everyone is going to be different, and this method wont work for those 2 shot a day'ers. but with sliding scale or pumpers, should be do'able.