Like all legal systems, canon law provides for exceptions where the general rule is not appropriate. The Code of Canon Law uses the Latin word “nisi” or some equivalent 1300 times, indicating that an exception is about to be made. In 1622, Pope Gregory XV issued a general decree requiring everyone to denounce to the bishop or the Inquisition a priest who solicited sex in the confessional. In 1842, Pope Gregory XVI provided an exception for those living in the lands of “schismatics, heretics and Mohammedans”, the repressive regimes of the day. Further, in 2011 the CDF asked all Catholic bishops’ conferences to send in their child abuse protocols for checking. If they are approved under Canon 455 they become canon law for those regions – as happened for the United States in 2002. Such protocols can be tailor made to cover all the variations that you mention. Canon law has borders if the Pope wishes to create them. This is an unconvincing excuse.