IMHO, CDU's are more useful for solenoid coil point motors which require a brief "kick" of high current. solenoid point motors typically have three wire connections (two coils and a common) and work with either AC or DC (without requiring any polarity change if DC)
As Gizzy has said, LGB motors, being more akin to motor drive than solenoid drive, don't work in the same way in that they use only two wires and require a reversible DC feed. They need (arguably) a slightly longer pulse to drive the motor all the way over but don't need such a high "kick" of current.
(some very old LGB motors were three-wire and maybe were solenoid driven?)