How would 30% "come from the developer" of a non-custodial wallet? What developer, where is he involved in the payment loop?
Discussion
Someone created the app, someone put it in the AppStore, that’s the person that pays the fee.
As I said earlier, the developer is completely free to modify their app price to compensate for the 30%, but that also means the customer is free to not purchase it.
They need to decide what is more profitable, adding the 30% to the app price and losing overall customers or paying the 30% themselves and growing revenue by volume.
Neither