I have been considering this for 5.x as well. I just scheduled for 6.0 to not lose sight of it. If we do go for 5.x does this warrant a 5.3?

I think it partially depends on whether we do this as a separate module (ala hibernate-javav8), or if we see this "in line" with hibernate-core like we ultimately did hibernate-javav8.

In what JDK does the javax.money package get introduced? Until that time should we instead support org.javamoney.moneta?