Well they can "get away with it" or "justify it" becuase as long as you don't need to exceed the voltage of your battery in order to attain your desired wattage, then it's VW.
What pisses me off is that in their specs the list the output voltage range as "input voltage" when they should be calling it "output voltage". If they called it what it is, many people (but not all) would be able to discern that the mod has no boost. By calling it "input" they are essentially making people think that is the operating voltage of the PCB, which is useless info for most vapers anyhow.
They aren't the only ones who have done this. Devices without boost seem to somewhat common these days.
The way to tell is to look at the specs. If it doesn't show a voltage range (whatever they call it) above 4.2 volts, or shows no voltage range at all, then you can almost safely assume it has no boost. Then you can try to verify this with review videos. However I have found that 99% of reviewers are oblivious to this and don't even test a mod enough to figure out that it has no boost. One reviewer who shall remain nameless, actually half-figured it out and said that the mod was defective, when in act it simply had no boost. But he had no concept of the concept until he had Mooch explain it to him months and months later. Even then he barely grasped it