That it had to take Geoff Johns to come up with the most reasonable patch over 20 years later - that Clark was only Superboy in the 30th Century - still boggles my mind that nobody thought of it sooner.
Remember that they didn't remove Superboy from continuity because they removed his childhood adventures - that's backwards. They removed his childhood adventures because they removed Superboy. Byrne's reboot made him not powered as a kid. Making him 'only Superboy in the 30th century' isn't a reasonable patch when the whole point is that he couldn't have been Super period.
It wasn't until Johns retconned Byrne's retcon because he actually thinks Superbaby is a good idea that Clark participating in the Legion as a kid again became a plausible restoration.