Nice early impressions. I dsagree with this though
''I do feel also that cable choice/upgrade is rendering much more meaningful advances in sonic quality than the change in IEM body and internals(?)''
It's a combination of both the technologies going into the new product as well as those cables. The reasons the 1Plus2 scales up so high is because they are that resolving of the source. So in effect it is the IEM as well as the cables. That includes the shell design and the acoustic dampening they use in their IEM along with the tuning and parts. So its much more complicated than you'd think.