Currently if a user changes the tracking mode from Steam VR to Desktop or custom the anti-aliasing setting will be set to None despite saying that it is set to something else such as MSAA x4.
This is expected to be fixed in a future release of Visionary Render but until it is fixed a Create Event with the following script can be implemented into your scenes as a workaround.
function AA()
local AA = vrSettingRead("Renderer/AA")
vrSettingWrite("Renderer/AA", 0)
vrSettingWrite("Renderer/AA", AA)
end
vrAddSettingObserver("valuesChanged", AA, "Tracking/Config/Mode")