It isn't, and the payment services regulation of EU actually might make this use case completely impossible here. All the payment apps that worked like this (on Android) were scrapped because of the regulation, and it's all through Apple/Google/Samsung Pay only now.

I really would like if Apple found a legal workaround, but I'm not hopeful.

How did the EU regulation that requires Apple to provide NFC card emulation capabilities to apps impact apps already doing the same thing on Android?