No peter. A player can sign a pre-contract agreement and a pre dated contract. The player is free on a professional contract to sign such agreements without any contact from their existing club providing they do not have a period of more than six months left on their existing agreement. If the club they have signed pre agreement with and contract chooses to register that contract then it is valid if the player has subsequently signed with a second new club then this agreement cannot be effective due to this first contract it is a nullity unless the first club chooses to waive their right under the agreement which as you point out would be the wise thing to do as the player would be unhappy. The fact remains that the club could enforce their pre agreement and registration. Your last paragraph is wrong however, the SJFA rules do not ban signing players, it brings in moratorium against registering players which is effective until June.