Hey @Tynnor,
I’m sorry no one got back to you sooner. I’d still like to answer, since other users might search for the same information: Since you posted, we’ve moved the stackups into their own articles. The one you need is 4 layers 1.6mm 35µm stackup. There’s a separate article if you were on 0.8 mm.
We don’t publish a loss tangent for pooled production. If your design depends on one, get in touch before you order and we’ll look at what’s possible for you.