This should be a pretty well-known attack by now.

I remember that Kraken allowed free lightning withdrawals though.

> Which wallets still exist that are custodial and that do free withdrawals?

Asking for a friend? haha

> Is it WoS?

No, the post mentions they actually had the best security among those tested:

> **6. WalletOfSatoshi**
>
> WalletOfSatoshi charges the user the exact fee for the routing. It also does hold a reserve of 0.3% balance in case of unexpected high fee. This is the most conservative take together with that of OKex, in turn making these two services the least user friendly.

security

Stealing Sats from the Lightning Network Custodial Services (2022)

I have not tested this empirically (meaning I'm just going off the feels here) but I think most ecash wallets pass the routing fee on to the user when leaving the mint. Which wallets still exist that are custodial and that do free withdrawals? Is it WoS? I haven't used them in a good while...