I've pretty much abandoned BT for train control, I won't buy anything that doesn't have a real command option, Legacy/TMCC or DCS. My layout is only 12 x 24 with a yard extension, but I can't reliably run a BT equipped engine using a phone or the universal remote around the whole layout if I stand at one end. To me, that's absurd and detracts from the whole idea of command/control!
If I have to follow the engine around, why not just run a wire to it?
FWIW, I'm sure part of the issue is the location of the BT boards in diecast steamers, they're inside the diecast shell. The antenna is part of the little BT board, so how do they expect decent range with that design?