The antennas you linked use coax network phasing, the crosshair use vector phasing of the elements, this provide better match, better circularity and better efficiency.
This is where our innovation is, my stacked windmill also use this method.
Way before releasing the crosshair I showed it to an author of the ARRL book, he was impressed by it's simplicity yet excellent performance and recognized it as a genuine design.
No, but the wave trap is Alex's design. That don't stop anyone from getting monetary gain from it, however with how much Alex did bring to this community, I want him to keep going.now is the Helical also copyrighted?