Hello! I made some mock-ups concerning the Yaru support for Unity.
I stitched it from the available Yaru elements, but added those related to the Unity desktop, like the titlebar; close, minimise, maximise buttons; and different drop-down menus.
The icons here are Yaru’s folders and symbolics (both of which btw are fantastic!), mixed with the Gnome icons, for the rest of the set, without replacing any 3rd application icons. This is similar to how the icon set was in Unity, and I think it is better overall, than the current Yaru set, as the Gnome icons are quite nice and mix well with other shapes and colours. Additionally some Gnome icons may be combined with the Humanity or Yaru elements, like the sound file and the html link icons here.
The icons on the top bar are mostly from the unrealised Suru. Some, like the battery, network and keyboard layout icons, maybe mixed in from the old Ubuntu Mono Dark set, but modified to be of only plain colour, without any shadows.
And as Nemo is already being used to draw the desktop icons, it makes sense to make it the main FM.
I also added a bit of restyling for the very nice program called Gnome Sushi here, just in case.
Hope this may be of use to anybody and thank you for your efforts!