@BOB WALKER posted:BlueRailTrains uses BLE4 which has extended range. BLE5 will go further, but might be overkill for model trains.
Pretty much every version of bluetooth had good range if it was outputting the right amount power. I have bluetooth 2.1 devices that easily make 500 feet and almost a 1000 if they have external antennas.
The main focus of newer versions of bluetooth isn't really range but throughput.