I don't know because customer service handled it, but my understanding is that the account number can be left blank because Speakout doesn't use it at all, so only used to satisfy the forms and checks/balances on Public Mobile side.
An update to the porting out process from Speakout, from information gleaned after talking to Speakout customer service, and from multiple failed attempts by Public Mobile to port the number from Speakout:Porting via PIN only will work. Public only ...
