You are way more of an expert than I am with paint and paint products. In your experience, you probably have come across some odd combinations of products that work.
But for me, it is best if I stick pretty close to that the data sheet on the paint product recommends. I do not think it is wise to use a PPG activator in a Dupont paint, or primer, for example. I do not think SPI would recommend using some other companies activator, or hardener either, in one of their epoxies or paints.