It's in 3.8.33-beta, no launcher update is required. The launcher is ever improving though, so it doesn't hurt.
Proper retina support is still outstanding. We'll see if we can make it in 3.8. Multiple application windows will come in a later update, it's a big effort both for the windowing system / OpenGL and our view management.
Your websites are looking very good! Congrats!
Retina support is in 3.8.34-beta. It's great for fonts and the viewport images. The rest of the interface is still scaled, but it's a lot better. Scaling is controlled via the Interface scale
setting. Likely 100% is too small, though the interface will be crisp. 200% looks OK and things are the right size. I don't recommend using anything besides 100% or 200%.