Cashu is custodial. It's been said, it keeps being said. If you want trustless, cashu ain't it. If you move cashu from one mint to your own, you're better off paying a lightning invoice to yourself instead.

Stop striving for trustless and instead explore how much trust you are willing to embrace and for what value. Can you batch payments with a reasonable amount of trust?

Also, don't recommend cashu as a trustless tool to others.