Just a thought...
I didn't think I vaped tobacco, and on another (non-UK based) subscription service I selected the non-tobacco option. Then I went to Vapefest, and bought 3 different Manabush, and Mrs Lords Navy Cut. I still won't be changing my sub to include tobacco though!
Anyway, last month that other service sent 2 bottles of tobacco to their non-tobacco customers. I don't know whether they were sent because the service was short on non-tobacco's, whether it was a mistake by the company, or whether the company had made the decision on behalf of these customers that they would (in effect) overrule their instruction to not send tobacco.
One the profiles says 'blend of two vanillas, creamy caramel with a backnote of tobacco' and the other 'burley tobacco mixes with chocolate cream and caramel".
I don't know how tobacco-ey they are - they're probably not very, but their customers hit their Facebook group expressing dissatisfaction (to say the least) that they had been sent them and it all got a little moody for a bit. That company ended up sending non-tobacco replacements out for those that requested it, but I think it annoyed quite a few people and didn't reflect too well on the business that sent them.
If you do send the Manabush, and you should - it's great stuff, even for a non-tobacco vaper, would you consider dropping a little note in with it just explaining to your customers that whilst it does contain some tobacco flavour, you're confident that it's such a subtle backnote that they will still enjoy it if they give it a try? Or something similar, I don't know.
You already offer a refund for those who don't like the complete box (which is pretty cool) do you have a standby in case your non-tobacco's definitely don't want any tobacco at all?
You know your customers better than anyone, but it's quite a strong decision to send something that people have said they don't want and I just wouldn't want you to experience the negativity around that decision that the other guys did.