Could it be sucralose that you're not liking in the juices? I know that GLV uses sucralose for sweetener. Not sure about Nicoticket though.
As a test maybe when you get supplies... Mix up some PG/VG by itself in one bottle. In another bottle mix PG/VG/Sucralose. See if the sucralose bothers you.
Just an idea.
MBV has a wholesale site where everything is cheaper in bulk. If you want to get their flavorings I would check that out.
As mentioned they use Flavor West so it's probably cheaper to order directly from them.
For the recipe I would do 5% each of Vanilla Butternut and Cinnamon Roll both from Flavor West. Add maybe a percent of EM if any. Adjust the percentages from there.
Where is this MBV wholesale site you speak of?
I would like to use the Flavor West Cinnamon Roll but their site says out of stock. I wonder how long it takes them.