It's been a while since there's been any update on the Netbeans plugin for Echo2, due to a lack of time on my part.
But, fortunately things are moving again. A new team lead by Jindra Sedek from the University of Prague is taking over in order to complete it as part of their semestral project (including possibly a GUI builder). Watch the website for any progress:
https://nbecho2support.dev.java.net/
Cheers, Jacek