One helper per engine. Both the public API below and addSyncTransport need one, and two of them on the same engine means two identical per-frame diffs and every onEnterScene callback firing twice.
addSyncTransport
onEnterScene
One helper per engine. Both the public API below and
addSyncTransportneed one, and two of them on the same engine means two identical per-frame diffs and everyonEnterScenecallback firing twice.