I mean during Morrison's Final Crisis were we not introduced to at least 50 different Supermen? All of these characters were the Supermen of their respective worlds. And among them we had guys that didn't even look like Superman at all. We even had Cap. Atom from earth 4 who had quantum powers and could grow to different sizes, multiply himself and use the influence and use the 4 laws as he pleases.
Was that anything like Superman? No. But was he interesting and still considered a Superman never the less. The original Cap. Atom who was in the same use as the question was actually based off of Superman and that is why Grant considered him a Superman.
We can also look at Cap. Marvel who is a magical Superman....You see where I'm going with this right? All of them are Superman just changed around enough to become a Superman and something more to make them there own character but the idea of what makes Superman who he is still remains. Why can YJ Superboy of earth 16 have the same?? He meet the only criteria needed to: He is from a new earth and he's not the Superboy you grew up with.
Also in the 1980s Superman was given TTK to explain his powers so even though he still showed all of his normal powers they in reality were not his normal powers. They were all explained mostly with TTK.
-Instead of having hard skin he had TTK
-Instead of having super strength he had TTK....so on and so forth
Now look at Superboy YJ and Superboy 90's:
-both have strength
-both have durability
If they come up with a way for him to fly then they will have that. What I'm getting at is that You saw how they changed Superman in a pretty big way in the 80s but he was still Superman. Why can't Superboy do the same??
Yo gotta see that this is a new and different take on the character.
Again though stephens I'm truly sorry if I came off as just arguing but I'm not I'm debating. But I gotta still let you know that I respect you and your thoughts (I always have) and I see you as a friend.