A stepper motor can be operated via motor cables up to several meters long. However, an LC network on the PCB, and shielding of the cables is recommended in order to optimize electromagnetic emission.
Basically, resistance and inductivity of a long motor cable is not a problem, as the coil itself is a long cable.
Capacity between conductors and GND can be tolerated up to a nF or so - depending on sense resistor and blank time (increase this if necessary). The capacity in between of cables of one coil has the same tolerance.
Capacity in between the different coil connections will disturb the chopper as the edges of one switching event inject current into the adjacent coil and thus trigger earlier / later chopper action.
For optimum performance, shield coil A and coil B cables separately, or at least use a twisted pair cable for each coil.