Hi Alex,
today I finally got my Samsung Z2 to make some tests. It took time to arrive but finally here we are.
I can confirm that what you suggested works: symbol and dll for WebGL are working fine. I managed to reach the ending part of the build without any success, not because of PlayMaker but because of a weird signing issue. Moreover looks like two people in the entire planet managed to compile, deploy and put in the Tizen Store a game.
Situation looks desperate to me, but hopefully this is my perception after an entire day of builds with errors, rollbacks, patches installs and reading about the same frustration on forums and blogs.
Thank you for your support!