I know I'm not the first one to have noticed this, that even though it took Superman a good number of years of yellow sunlight exposure to get to his current power levels, all a Phantom Zoner/renegade Kryptonian/what-have-you from Krypton has to do is catch a few rays and up he goes, lifting freighters, blasting away with heat vision and boasting some brand spankin' new invulnerability.
My question is: Has any writer ever addressed this discrepancy? Any kind of explanation, like adult kryptonian metabolism adapts quicker to yellow sunlight, or something? Was Kal-El rubbed with kryptonian sunscreen before he was put in the rocket, leading him to absorb less sunlight? Or is it just another one of those "let's sweep this detail under the carpet for the sake of the plot" contrivances?