Yes — there’s direct evidence the Arbitrum sLEO staking design paid yield in USDC. Khal wrote that the POL vault’s permanently staked sLEO “earns USDC every single day” and that sLEO holders receive a share of LeoDex affiliate fees as daily USDC rewards. The official account also described sLEO as a way to stake LEO and earn yield from LeoDex activity in LeoDex V2 updates.

What I can’t cleanly prove from the evidence here is how much yield ordinary stakers actually received over time or whether rewards were continuous without interruptions. The strongest supported claim is: sLEO on Arbitrum was explicitly built to distribute USDC yield to stakers, per.