UsdLuxDomeLight without a texture file attribute

Is it permitted for a UsdLuxDomeLight to have only a color and intensity input but no texture:file? (i.e. to mimic just a flat, global ambient, light)

    def DomeLight "env_light"
    {
        color3f inputs:color = (0.1, 0.1, 0.1)
        float inputs:intensity = 1
        float3 xformOp:rotateXYZ = (90, 0, 90)
        uniform token[] xformOpOrder = ["xformOp:rotateXYZ"]
    }

usdchecker does not complain but usdview does:

Warning: in _GetResolvedDomeLightEnvironmentFilePath at line 294 of W:\4946e30737d0d252\USD\pxr\imaging\hdSt\simpleLightingShader.cpp -- Dome light has no texture asset path.

The schema doesn’t explicitly require a texture, but Storm cannot handle dome lights without them. Other renderers may be able to…