If I set “dataMappingMode = DataMappingMode.OpenInterest” and I'm using Minute resolution with extendedMarketHours = True, I see that the OnData price data rolls from the old contract to the new contract at 17:00:00 ET.  However, I do not get the SymbolChangedEvents notice until midnight.

Pretty minor issue I think, but it seems both should happen at the 17:00:00 time slice?