A vibrant and opaque orange paint is a rare thing period! Both pigments required to form a great orange are, themselves, really transparent, so some form of white is gonna have to be used to add opacity (I know that many modellers see white as a tricky pigment to get good coverage, but this isn't the case in the broader spectrum of paints. Of course, the best white was lead based, and not popular with the H&S brigade). As you rightly say, you can add a flat coat to a satin orange -
model air 71.083 is a cracking hue - so all is not lost! The bottom line is that manufacturers are squeezing a little pigment quotient into their paints as they can get away with, it is, after all, the most expensive element in paint. I've been using the stuff for 45 years, and its unrecognisable from the same stuff I used to use decades ago.