I'm surprised no one suggested cutting the TFA Cinnamon with PG. Maybe 1:1 (50%) or 1:2 (33%) or 1:3 (25%) something like that. So if the Cinnamon is only 25% of the diluted flavor, then it would take 4 drops to equal one drop of the full strength, making it easier to control, especially in small batches. This is what I'll do if I get around to ordering the CAP flavors I don't have for this.
ETA: since there are typically about 20 drops per ml, at 0.1%, that would be about 1 drop per 50ml, not 30ml. I know some people come up with up to 30 drops per ml, depending on their dropper. At 30/ml the one drop per 30ml would be about right. But every dropper or blunt tip syringe tip I've used is more like 20. I've never tested those pipettes.
ETA: since there are typically about 20 drops per ml, at 0.1%, that would be about 1 drop per 50ml, not 30ml. I know some people come up with up to 30 drops per ml, depending on their dropper. At 30/ml the one drop per 30ml would be about right. But every dropper or blunt tip syringe tip I've used is more like 20. I've never tested those pipettes.