In general, I recommend models do not sign a commercial release for test and TF* shoots. There are cases where it is worthwhile for a model to allow commercial use if the advantages offered by the photographer justifies such broad ranging usage. Those are pretty rare occasions. Many photographers will try to get models to sign a commercial use release telling them it's a standard release. I also recommend against signing a full commercial release on the promise of future percentage earnings. Those rarely amount to anything worthwhile.