“Shader error in 'Hidden/VFX/.../Minimal/Render Quad': undeclared identifier 'mainTexture' at line 2198 (on d3d11)” error appears when connecting a Switch Node output to the Main Texture in VFX Graph

Reproduction steps:
1. Open the attached “VFXURP.zip” project
2. Open the “SampleScene” (Assets > Scenes)
3. Open the “Main Texture Bug Demo.vfx” from the Project Window
4. Click Compile
5. Observe the Console

Expected result: No errors or warnings
Actual result: “Shader error in 'Hidden/VFX/Main Texture Bug Demo/Minimal/Render Quad': undeclared identifier 'mainTexture' at line 2198 (on d3d11)” error

Reproducible with: 2021.3.45f1, 2022.3.51f1, 6000.0.25f1, 6000.1.0a2

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Notes:

• Error might appear instantly after opening the Editor or after a fewer steps
• Does not reproduce in BiRP and HDRP