Stadiums are just not set up to accommodate such a policy. It would never get past the SAG.I dont think there is a solution that Argyle could come up with that solves the problem.
The only way it can be sorted imo is for the stupid rule limiting the allocation to be changed.
The FA Cup is a knockout tournament and so the allocation of tickets should be 50:50 giving the fans of both teams a chance to support their team. A cut off date for the sale of away tickets should be notified at which time any unsold tickets provided for the away team are returned for home fans to buy if they want them.