treeag Hidden Traits Unlocked was the first to edit the Traits.xml to unlock hidden traits, I edited the same resource to upload Lower Lifetime Rewards, which was taken over by Ellacharmed Lower/Higher Lifetime Reward Prices in my absence, and several people uploaded versions of traits unlocked for younger sims:
jimmyThePipe More Children LTR and Traits
joninmobile Unlocked Traits for babies and Toddlers
Chicken0895 Unlocked Child/Teen LTR and Traits
All of these mods edit/alter the same Traits.xml and was first combined by claudiasharon's Hidden Traits Unlocked and Lower Lifetime Rewards which was last updated for patch 1.26, but also includes All Traits and Lifetime Rewards for All Ages.
All traits and lifetime rewards were made available to Babies to Elders, the default limited babies, toddlers, children, and teens on various traits/rewards.
Hidden Traits unlocked
various versions for lifetime reward prices, either higher or lower depending on which you prefer