I think that this is exactly what Lionel should do, is start selling Lionchief with Bluetooth, upgrade electronics for conventional trains. They could do a base version, and Plus kit with operating couplers etc. Also, there would be separate upgrade kit types for different motor types, so the upgrades could be done for postwar and more recent can motors. They would then sell a ton of thier Lionchief multiple loco remotes, and could monitize thier app for the use of Bluetooth.
Ideally, it would also be setup so that similar locomotives can run in multiple unit consists for diesels and double header steam.
I think they would then sell a ton of thier Lionchief multiple loco remotes, and could monitize thier app for the use of Bluetooth. For the upgrades, If they could make it easy enough they could enlist the hobby shops to do some for customers who can't figure it out