At present, parental controls to set Xbox permissions don't deal with screen time limits – and Microsoft's family features, such as screen time limits, are available only for Win 10, Android, and Xbox consoles, not iOS devices. Will "account migration" as referenced by [Mojang] Ined above be able to address the problem?
Thank you @valkyrie_pilot – do you know of a thread where this is being addressed for iOS, since the issue crops up there as well? Thanks.