Well, to be precise, if you added 2tsp of your 2:1 mix you would be adding 1tsp and 1/3 of a tspThe 1 tea PPO is dry, so if you do a 2 to 1 mix, then you would need to add 2 tea. Or just add what you want to get the color you want.
Minute 9:24 ...So does adding TD to some extent but if your temps are low and you use it for just a few seconds you should be fine. I absolutely cannot incorporate TD into my batter without it. My other micas I stir/whisk in fine. TD is a different animal in my experience. Like I said before, try it...you might like it! I use very little TD to get a nice white. The stick blender is the secret.
Here's a thing. This website suggests that one US teaspoon of titanium dioxide weighs 21 grams!!!

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One tsp of TD (with my tsp measure thing) weighs 3.65 grams
Could someone tell me how much your teaspoon of TD weighs, because if I'm putting in 3 1/2 grams and you're putting in 21gms then I think I have solved the mystery of my invisible TD