After having great comments and motivation from your comments, I would like to share another idea in before filing an issue.

Composing a new constrain based on other constraints are frequently used in our production systems. However sometimes I was desperately desiring an option to display message by violating constraint. It can be considered this option as complementary option for ordered constraints. Ordered constraints are discussed at another topic but for composite constraints It can be great to option select message source. Parent (composer) or child (composed) message source.