It's cool because its like WoS but open protocol, you get an LN address, and you can choose in wich mints you trust, and you can send cashu offline or in a text. So yes it's just custodial LN with some extra feats. The potential to get rugged is in every custodial, maybe some shaddy mints are more likely or likely to shutdown than WoS but it's just a matter of choice. Non-custodial LN is though, expensive, most don't have LN address.