Something is bugging me.

Over lightning, sender privacy is good.
Over lightning, receiver privacy is bad.
Over ecash, receiver privacy is good.
Over ecash, sender privacy has a middleman.

Of course the mint doesn't know who you are, or what your source of income is, but they may know the target payee... Doesn't this open the door to potential censorship? A mint may refuse to perform the payment.

Also, seeing that the original tokens remain valid upon a payment failure, those tokens can just become blocklisted (breaking fungibility).

Correct me if I'm wrong, but it seems as if cashu improves receiver privacy, but can compromise sender privacy/targetability unless a proxy is used when making payments.