While this is no real consolation for GA fliers, with airliners it is possible to activate the toolbar and interact with the panels while in VR under a very narrow set of conditions.
This at least allows for IFR flights under VR using ATC etc.
If you change views to one of the showcase “fixed” views, the views that put you inside the aircraft overlooking a wing or an engine, as if you were a passenger, then from that view point it is possible to both activate the toolbar while in VR and interact with the panels.
Note: In this view point you would also have to close the panel again before reverting to cockpit view as the panel will remain on the screen and become un-interactable with once again.
It is enough of a workaround to keep me using VR for airline flights.
GA aircraft, to the best of my knowledge, have no such fixed views that are inside the aircraft and so this workaround won’t work for them.
(Note: I can’t claim credit for this discovery- someone else found it)
Update: This method might be more useful: https://forums.flightsimulator.com/t/toolbar-broken-in-vr/472150/106