As a self-custody maximalist and as I'm worried about incentives in nostr I would argue that the client devs should do this for a profit. Now hear me out ...
If you rotate "trusted" mints, you herd people to trust the one or the other mint and some of them will inevitably pull an FTX. Chaumian Mints are not able to eliminate the quick rug pull problem and trusted parties remain trusted parties that we should try to keep as minimal as possible. I would want fist-reach custody. My family mint etc. And nostr clients approving mints as trusted and websites ranking mints by user trust are only leading to concentration, increasing the stakes for attackers.
Why not have a client and relay tax associated with those predefined mints? Make it a monthly fee. $5/month and you get NoStrudel "purple" automatically even if you don't get zapped $5 ever. Make it 5% of last month's zaps + $5 if funds are available.
* Users can instantly receive zaps
* Users can completely avoid paying by moving their sats to another wallet
* People **will** avoid these fees unless they really want to support the client devs and relay operators this way
* Nobody ends up prescribing a trusted mint
For this to work, the mint would have to ask for the "tax" payment when redeeming tokens received to npub or something but I guess it could be done thanks to zaps to npubs not being as private as Chaumian cash otherwise would be.
Am I right to assume that a payment to npub would only encrypt the token with the npub but otherwise not let the mint know about it being related to an npub? So I could still DM an encrypted token to Alice and she would receive it on the mint without the mint knowing it was to her npub?