An Auto male, from the same cross would be ideal, but absent that I would go with a backcross with the original father. Just to bring the autoflower trait to the surface. Then see how the flavor, and high compare with the original mother, before deciding which direction to go with the next breeding step.
But I am just a hillbilly that likes to play with different crosses.
Best of luck bro.
And Congratulations again.
HomieHogleg