Using the OnDemandRendering API commands such as OnDemandRendering.renderFrameInterval yields Exceptions in the console in Play Mode.
They don't seem to be erros int he user's code.

Repro steps:
- download this project
- run the BugReport scene
- notice the Exception:

UnassignedReferenceException: The variable m_RenderTexture of GameView has not been assigned.
You probably need to assign the m_RenderTexture variable of the GameView script in the inspector.
UnityEditor.GameView.OnGUI () (at <55cdba1bd6e14fba9b722ea76fea516b>:0)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <599589bf4ce248909b8a14cbe4a2034e>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
UnityEngine.UIElements.UIR.RenderChain.Render (UnityEngine.Rect viewport, UnityEngine.Matrix4x4 projection) (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.UIRRepaintUpdater.DrawChain (UnityEngine.Rect viewport, UnityEngine.Matrix4x4 projection) (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.UIRRepaintUpdater.Update () (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.VisualTreeUpdater.UpdateVisualTree () (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.Panel.Repaint (UnityEngine.Event e) (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.UIElements.UIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <4de086c5606b4c82839c6ab31c5b881e>:0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <ede85b10691a411faa239e6306258393>:0)

Reproducible in Unity 2019.3.0b1, 2020.1.0a4, 2019.3.0a7
Cannot repro in versions prior to the introduction of the OnDemand Rendering, like 2019.3.0a6.