I'm predicting attempting this would be more trouble that it's worth; however...
Scenario (numbers are obviously placholders for sake of demonstrating concept):
Sim A: #1234 Telecom XT
Sim B: #6789 2degrees
If one lodged simultaneous porting requests to transfer XT #1234 onto Sim B and 2D #6789 onto Sim A would the porting succeed?
Or does the act of moving a number off the 'Sim' (sim account) deactivate the account and make it ineligible to accept a port?
All input appreciated :)