It should be clear that InterceptionFactory.ignoreFinalMethods() only affects the generation of the "proxy" which enables interception. E.g. the following example would FAIL during validation of myFoo injection point (bootstrap):
The reason is that the CDI container must treat the producer as a deployment problem (unless javax.enterprise.inject.spi.ProcessBeanAttributes.ignoreFinalMethods() is used for the producer method).
I understand that it's not very intuitive. On the other hand, these are two different concepts. I.e. the injection point validation happens during bootstrap while the InterceptionFactory is used at runtime.