Are you aware of what
"Metaphors" are? This is literally what is being used here. The star system is actually a pocket dimension with mini stars and suns. It being called a cosmos or a universe does not mean it is one.
As for your "Universe" dimension, I checked the raws and No. It is not called a "Universe", nor was the dimension mentioned. So your entire "Universe"/"3-A" sized dimension argument gets debunked. Here
is the scan:
You don't have to copy and paste the whole thing to show me considering I was the one who upgraded the entire verse in this wiki to what it is currently. So I am aware of the entire thing. And it is highly relevant because your entire "Universe Dimension" argument is debunked. So yes, the extent of his amp is still unknown and it is a time-consuming process that requires the 4 quintessential elements.
Just FYI, D and Lefty do not get different ratings in AP or Dura. They are part of the same whole. What D can dish or tank out in base is the same as what lefty can do as Lefty is literally the left hand of D. So base D will not suddenly get a 3-A rating in dura with lefty (even though it is not 3-A anymore). If anything you can argue for
"Higher with Amps from Lefty" in AP and Dura, but that's about it.