Your nicotine already comes mixed in either PG, VG or both, so it wouldn't be a problem diluting it down. The only thing is the amount of nicotine you have in your batch will vary by how much flavorings you usually add. Say if you normally run about 20% total flavoring, and you have your nic base mixed down to 24 mg, this will put you at 19.2mg for your final product. If you use the same base with 10% total flavoring you will end up with 21.6mg nic. So you will have slightly varying levels of nicotine, depending on your tolerance this may or may not be an issue.