Hi Gunnar,
I've been looking through the (validator) code. In the ExecutableMetaData.Builder class there is a static list of rules, implementations of MethodConfigurationRule to be exact. If I read this correctly, if the OverridingMethodMustNotAlterParameterConstraints instance wasn't in the Set then that rule would not be enforced.
To implement that would mean that the "rules" Set would likely not be a static any longer but would be an instance field. When the "rules" Set is built it would add or not add some instances depending on configuration.
Does that sound reasonable so far?
...and maybe a stupid question but is there any easy way to get to the ConfigurationImpl? It seems like I'd have to pass configuration properties along on the stack (like failfast is done), which will make for some long parameter lists eventually.

Thanks,
Chris