To be honest, ditto for me.
I think it's assumed that (a) E-2 in the past is the Golden Age Earth, and (b) even if it's not the same Earth then it's firmly established in the Crisis that all the previous multiverse of Earths were erased one way or another and rebooted as a single Earth at the Dawn of Time.
That's where I get "frustrated"...so many people point out the Earth 2 Superman is NOT the Golden Age Superman...I simply forgive some continuity errors, because I can't see the "universal" differences adding up to much...or, I admit, I don't want to see it, because the original introduction of Earth 2 seemed to be in the spirit of reviving the Golden Age heroes, which I love...
