By way of an example, I was eating a salad which had raw onions in it. I then took a sip of Coke. The combination of the two flavours was amazing, but I know that if someone handed me an onion-infused Coke, I’d find it horrid.
What the hell is the difference?
With pre-mix you’re getting a continuous flow of the same ratio of flavors. No variation.
Mixing yourself, you have control over which flavor you want to be more prominent when.