boltz exchange is a piece of the flow, but imagine the user gets a fixed lightning address they can attach to their nostr key, then any zaps they receive there are automatically forwarded - at a certain threshold - to their liquid wallet on their phone
yeah with a threshold at which amount the forward would take place. or you could just use https://liquid.boltz.exchange
Discussion
If LNbits added liquid support, it could easily handle all of that.