ALL OU devices were constructed FIRST as small toy size demo devices.
Inventors learned how to SCALE IT UP.
My advice : look for small overunity effects first !!!! Understand them, later learn how they scaled it up and why it was possible.
Good observation....at least, regarding certain kinds of effects. Those relying upon mechanical force coupling effects may do better starting a bit large so as not to miss the 'aha' force intersections.
TS