Those early back-ups were mostly involved with goings on that were supposed to be resolved in the Earth-Krypton war--or War of the Supermen--but that landed kind of flat. It would have made sense to include some of those stories in the collected editions for New Krypton--but maybe not because there were so many unresolved plot elements.

Perhaps some of these stories will be included in a Legion collection--or in a 100 Page collection. The 31st century parts fit with ongoing Legion continuity, but the 21st century parts are probably no longer in continuity.