Single-pass instanced stereo rendering works again with LWRP.

com.unity.render-pipelines.lightweight/LWRP/DefaultRendererSetup.cs

-using System;
+using System;
 using UnityEngine.Rendering;
 
 namespace UnityEngine.Experimental.Rendering.LightweightPipeline
             foreach (var pass in camera.GetComponents<IAfterTransparentPass>())
                 renderer.EnqueuePass(pass.GetPassToEnqueue(baseDescriptor, colorHandle, depthHandle));
 
-            if (renderingData.cameraData.postProcessEnabled)
+            if (!renderingData.cameraData.isStereoEnabled && renderingData.cameraData.postProcessEnabled)
             {
                 m_TransparentPostProcessPass.Setup(renderer.postProcessRenderContext, baseDescriptor, colorHandle, BuiltinRenderTextureType.CameraTarget);
                 renderer.EnqueuePass(m_TransparentPostProcessPass);

com.unity.render-pipelines.lightweight/LWRP/Passes/DrawSkyboxPass.cs

-using UnityEngine.Rendering;
+using UnityEngine.Rendering;
 
 namespace UnityEngine.Experimental.Rendering.LightweightPipeline
 {
         {
             
             CommandBuffer cmd = CommandBufferPool.Get("Draw Skybox (Set RT's)");
-            cmd.SetRenderTarget(colorAttachmentHandle.Identifier(), depthAttachmentHandle.Identifier());
+            if(renderingData.cameraData.isStereoEnabled && XRGraphicsConfig.eyeTextureDesc.dimension == TextureDimension.Tex2DArray)
+            {
+                cmd.SetRenderTarget(colorAttachmentHandle.Identifier(), depthAttachmentHandle.Identifier(), 0, CubemapFace.Unknown, -1);
+            }
+            else
+            {
+                cmd.SetRenderTarget(colorAttachmentHandle.Identifier(), depthAttachmentHandle.Identifier());
+            }
+
             context.ExecuteCommandBuffer(cmd);
             CommandBufferPool.Release(cmd);