>>938
https://stepnofficial.medium.com/stepns-action-plan-for-game-economy-db67fcba405

＞3. The min/max attribute values of the new shoes will be increased by 20% (for example, a traditional uncommon sneakers’ attribute ranges from 8–18. If you synthesise 5 common sneakers, the synthesised uncommon sneaker’s attribute values will range from 9.6–21.6).

ってあるから間違いなくレアリティ上がってる