I'll expand this point more thoroughly on the list, but the tricky part here is that the Ruby code is relying on a *static* method from the BlockProcessor implementation class. By the time the constructor is invoked, it's too late. The chicken and egg problem here is that we need to convert the config Map to a RubyHash w/ symbols without having access to the Ruby runtime instance. I'm calling the static setup method from the ExtensionRegistry to perform this conversion lazily.