Assuming there would be no problem physically accommodating the cable terminations, the only situation I can envision in which that may not be a good idea would be if the cable is one of the few types that have ultra-high capacitance, such as Goertz. Having two runs in parallel will double the total capacitance, which may be a problem for the amp if the capacitance of a single run is already very high. Two runs in parallel will also result in resistance and inductance being cut in half, which can only help assuming the goal is to minimize the sonic effects of the cable.
Regards,
-- Al
Regards,
-- Al