It only matters when there is a problem. Mainly because automotive paint manufacturers, have No interest in seeing their products used on models, therefore they don't formulate for our needs. For modelers its adapt, and learn sometimes things work out other times not. I have recently attended a John Kosmoski Seminar, John is the original developer of House of Kolor paints, He would like a Painter to use HOK products exclusively from start to finish. This system will price you in to the Hundreds of dollars when all is said and done in supply costs. You will have enough paint to cover maybe 10 Models all in the same color. However if there is a Problem you have Recourse. If you use HOK with store brand reducer" as others have done" and your models look ok ,but slowly start to change to rainbow colors then explode, and you know it was a fault with the paint.You can call John He will listen to your story, then tell you there is nothing He will do for you. because doing so will be admitting fault with the product, and things go South from there.
If I go to my paint Jobber He mixes the same colors in the House brand as HOK. Usually in Diamont, or R&M, brands and recommends the generic mid temp reducer for that. Then we are Rockin and a Rollin for way less than HOK.