I think Alter Egos, when created by the player, should have the option to be company-exclusive or free to use elsewhere. This could be used to simulate when people get their names or gimmicks from smaller indy companies and use them all over the scene, or ex-WWE guys promoting themselves under their WWE names. I also just think it'd be useful to be able to do this since there's no way for workers who randomly generate into the game world to gain a new name besides their debut/shoot name without manually editing them in the editor.
I also think that in the Regeneration settings (in-save editor, where you can Enable or Disable the setting) there could be an option for only "Legacies" to regenerate. While this can be set up in the editor before saves, it again requires manual editing in the middle of saves to only have masked generated workers regenerate as legacies and prevent non-masked workers from regenerating. I may be in a small minority, but I prefer the regeneration mechanic to only be used for masks and legacies, so I think a setting like this could be useful.