I liked progression in the classic Legion of the 30th/31st century and the original Earth-Two JSA--because in both those cases there was a situation that allowed real time in the comic book. I could believe that the Legion started in 2958 and that time kept passing for the characters--but because of science in the far future age was a different thing (you could be a teen for decades). I could believe the JSA formed in 1940 and some characters aged while others were immortal or semi-immortal and didn't age as much, but everything on Earth-Two was set in real time.
In the mainstream comic books, how do you make it work? It seems scatter-shot, where characters age at different rates. Sometimes children grow up fast, sometimes they don't. And there is no such thing as real time in the comic book. So why are these characters being aged at all? If in twenty years, a character ages five years, why does that happen? There's no comic book science that explains it.
If you want characters to age and change and have kids and see those kids grow up--then you should advocate for a comic book world set in real time. I think that could work--but it would probably have to be a separate imprint where this is the rule of the universe.