This MRC controller uses the 'autopulse' feature I published some 20 yrs. ago in a forum.
(Although I would suggest a 3k3 resistor, instead of the 10k, for very good crawl behaviour)
When fed by DC, it will just not pulse, but the reversing will not be affected.
No, the Bachmann seemingly uses the positive and negative half-waves for direction,
maybe also a Triac for speed setting,
giving some acceptable, albeit noisy, slow-speed performance for standard iron-core motors.
Do not use it with can-motors, as it may burn them out.