While there would be no patent attached to any seedlings, it's most likely somewhat early for anyone to be growing seedlings from them since they're relatively new to the market. That's not saying that nobody is doing it, BUT since these are hybrids (the whole series) between acer psuedosieboldianum x acer palmatum, it will be a real crap shoot as the which parent the seedlings most resemble, and they hardiness associated.