And I still don't understand what it does, why I would need it. I need an explanation like I'm 5.
Reading your github confuses me even more, something about a wallet... but normal less technical people would not understand that jargon.
Discussion
no one can answer why you would need it other than yourself. A custodial mint that plebs can run for their friends on top of their lightning node with the main benefit being privacy for users towards the custodian. Users can pay others users with high degree of privacy and pay or receive lightning invoices as well.