You can run an MTH in "conventional mode" with the addition of a Lionel Legacy powermaster through the Legacy remote.
This will allow conventional operation via the Legacy handheld , which also allows control of the whistle, bell, electrocouplers from their respective buttons/controls, as well as access to some of the PFA's via keystrokes outlined in the powermaster owners manual.
I have operated MTH PS2 locos conventionally via the older Lionel TPC unit which the Legacy powermaster replaces. MTH locos ran very well, and once under way it was hard to tell they were being operated in a conventional environment. Smoke volume is adjusted through a smoke potentiometer screw on the loco, and they smoke just as well as under DCS.
The BCR in the newer MTH as well as the batteries in the older models prevents the sound drop outs during conventional direction changes.