I think that malicious compliance all the way might have been the better option here. If a birth date is all that is needed, let the user enter a random one. If actual biometric verification is needed alongside, let the user also paste the code to a fake biometric validator that always returns valid. It is the same philosophy as with an app that forcibly wants an invasive permission to the detriment of the user. Let…
You'd need to closely read the law and have a lawyer advise you, but a neat attempt might be to just ask for the date of birth, send that "in real time" to the App Store program, and then have that program simply discard it? I don't think current iterations of the law require that this be sent off-device in any way.
age age >= 13 && age age >= 16 && age age >= 18
A non-maliciously compliant implementation would need to retain a date of birth or equivalent until the user was over 18.
A maliciously compliant API could just wait 18 years after account creation before yielding an answer. (remember folks: "real time" does not mean "fast").
One of the oddities about the way the law is phrased is that it requires the age band information about the user be provided to "the developer" rather than to the application.