The drop down menu you've shown is covering up a Transparency checkbox. That's what you use to make it be transparent, it now matches how Photoshop works (you choose 24 bit and transparency, instead of choosing 32 bit).
Aaah OK. I did think that might be the case but it doesn't work for me.
The files all come out with a matte white edge as if it was a binary transparency.
This file ( Even when it uses the preset PNG-24 instead of [Unnamed]) :
Comes out like this if I load the PNG in photoshop and put a black layer behind it:
This happens even with new files. The legacy export works fine though.
Your later picture didn't show up, but I tried tests. It's behaving as if it's premultiplying with the stage color. Try a black stage, you end up with jaggy lines.
Can you submit a bug?
I hit submit too early It should be there now.
Yeah you're right, it is getting pre multiplied. I set it to black and the line edges are now black, but still with a jagged binary alpha.
Thanks I'll submit a bug.