If you recall from my review, one of the main criticisms that I had for Amod/Wotofo was their sloppy and unorganized dissemination of specs for the Yihi chip. I listed the specs as given by Amod to show how poorly it was done, not as an affirmation of accuracy ..
Yes, of course I tested the buck circuitry, that is how I know that it steps down. As I said in my review, it is not Amod who verified the buck/boost converter, it was my own direct testing and use of the device. For example, I have a 1.2 ohm build on the Wotofo right now set to 8w and firing at 3v, that is clearly stepped down voltage output, and also clearly lower than the 4volts minimum listing on Wotofo's shoddy specs. Put the same atty on the Robbot ZNA, set to the same 8w which does not have buck circuitry and you get a too low wattage warning, and the device will not fire at the stepped down voltage for that build.
Some of Amod's alibaba listings also say that their ZNA has a built in 2400 mah lipo

... you get my point? Hence my criticism for them ;-)