Like most things in Life, there are Good and Bad points to everything. Using Drops is No Difference.
To me, counting out Drops of Favoring and Sweeteners is Far Outweighed by the Hassle of Measuring and Washing Everything after using it once.
Also, most of my Recipes call for more than one Flavoring. I'll add a Drop of Pineapple and 2 Drops of Cherry to my DIY Watermelon Mix. Kinda hard to measure 1/38th of a ml of Pineapple and 1/19th of a ml of Cherry. LOL.
Pre-Mix and Drops works Great for me.
But if a person wants to Measure Every Thing, that's Cool Too.
LOL, hear you zoiDman. In the end, I often wind up doing much like you are doing anyway.
For example, the other night I made 60ml of a chocolate base of 6% PA Malted Milk and 3% PA Double Dark Chocolate.
I like it as is so I always keep some in my collection. But, I also like to draw out 5ml, and experiment with additions. By the drop LOL.