Transparent NSHostingController in SceneKit

I'm doing an experiment integrating SwiftUI views as Materials for a SceneKit scene SCNPanel node.

It is working perfectly in iOS using UIHostingController with the following code:

Code Block Swift
func createInfoPanel() {
  let panel = SCNPlane(width: 6.0, height: 6.0)
  let panelNode = SCNNode(geometry: panel)
  let infoPanelHost = SCNHostingController(rootView: helloWorld)
  infoPanelHost.view.isOpaque = false
  infoPanelHost.view.backgroundColor = SCNColor.clear
  infoPanelHost.view.frame = CGRect(x: 0, y: 0, width: 256, height: 256)
  panel.materials.first?.diffuse.contents = infoPanelHost.view
  panel.materials.first?.emission.contents = infoPanelHost.view
  panel.materials.first?.emission.intensity = 3.0
[... BillBoardConstraint etc here ...]
  addNodeToScene(panelNode)
}

Yet, when I tried to apply the same to macOS, I don't seem to be able to make the view created by NSHostingController transparent.
Invoking <infoPanelHost.view.isOpaque = false> returns an error, saying isOpaque is read-only and can't be set.

I tried subclassing NSHostingController and overriding viewWillAppear to try and make the view transparent / non-opaque, to no avail.

Code Block Swift
override func viewWillAppear() {
  super.viewWillAppear()
  self.view.wantsLayer = true
  self.view.layer?.backgroundColor = NSColor.clear.cgColor
  self.view.layer?.isOpaque = false
  self.view.opaqueAncestor?.layer?.backgroundColor = NSColor.clear.cgColor
  self.view.opaqueAncestor?.layer?.isOpaque = false
  self.view.opaqueAncestor?.alphaValue = 0.0
  self.view.alphaValue = 0.0
  self.view.window?.isOpaque = false
  self.view.window?.backgroundColor = NSColor.clear
    }

Tried setting everything I could think of to non-opaque as you can see, and still, the panels are opaque, show no info, and obscure the 3D entity they should overlay...

Can someone please advise?