I find myself missing the pre-Crisis and post-Crisis (pre-New 52) versions of the DC Characters and feel that Convergence, as silly as a lot of it was, was a nice romp through different eras.
I’d love to see DC bring back the old Showcase series but each book or arc is set in a different timeline or version of the DC Universe. They could easily explain in the first panels where this is and we can dive into some Flashpoint stories, pre-Crisis, some of the old “imaginary” Superman stories, Batman Brave & Bold team-ups continuing the spirit of those old books, Booster Gold in time, maybe close off some storylines that went nowhere when we jumped ahead a year or New 52 was created, etc. Even if it was just released digitally only as a DCU exclusive, how much fun would this be?