Hi, Sverige.
In a laborotory, Einstein would have been beside himself trying to calculate the exact number of Turmeric molecules actually in a Mixed Powder and the exact ratios of it to other spices. In the kitchen probably not. This is unfortunately what I wasted some time on at the start. When I first came to this forum the concept of Mixed Powder / Mix Powder / Curry Powder confused me for this very reason.

As I recently posted, I've come to realise that a measure of "Curry Powder" (brand unknown) in a "BIR Mixed Powder" doesn't really matter at all, because it isn't scientific at all. But will the actual curry powder you use make a difference? Of course it will. If you look long enough at the videos you'll eventually hear that
brand doesn't matter as long as it's a good quality one. In the UK, Rajah seems to be the default, but I've seen CT use a HOT Madras Curry Powder in one of his videos. That doesn't matter to me now because I understand it.
A beginner might not.
There is a Base Gravy video on YouTube (I can't remember which one, either H4ppy or JV or someone else) where he says he adds Mix Powder and then states that it's what the BIR's call Curry Powder. "Hang on a minute! What did he just say?" To a
beginner, the concept of a mixed powder, apparently also known as curry powder, containing Curry Powder, which is a mixed powder, as an ingredient, can be a bit heady.

LC has raised a fair question on the use of Garam Masala in Mixed Powders. It isn't just a matter of if it should be used or not, but also if it is used, which one. There is no answer because there are no rules or scientific laws.
Which Mixed / Mix / Curry powders do you prefer in Sweden?