It may not have to be a copy of the design but I'm frankly shocked that in the five or six years since Xin came out with the SuperMicro, no one's been able to come even close to the density of performance/size the micro has (besides maybe Ray Samuels, but he still has a ways to go in the size). I will make a note that I've never heard the SuperMicro but all the reviews I've read about it are raving, and I don't recall reading many negative reviews about it. Maybe amp designers are wary of making an amp that small, since small is usually equated with cheap?
As for the copying argument, there are plenty of chinese amp makers that have no shame copying other designs - the Matrix M-stage/Lovely Cube, Grant Fidelity, HLLY, etc etc. Sure, these are desktop-sized amps, but there's plenty of portable amp makers.
Given the size of the SuperMicro I'm a little bit surprised that you can even fit $100 worth of parts in there, much less $190. I wonder what the parts of the SM actually cost. IMO if someone decides to "copy" the design there's probably a lot of money in it for them.
I very sure the components of SMIV is not worth $100. But in audio, we are paying for their R&D and sound
The copying part, I'm sure most of us will go with the more reputable/original maker. There is reason why those shameless makers did not make the mark. Even Little Dot, a chinese base company is being copy.