Alternative to overriding Module::fromJson?

Reminder of the problem: my existing v1 modules save data in the root of the module JSON serialization. In Rack v2, would this be an acceptable solution to access the root JSON?

MyModule.cpp:

void MyModule::fromJson(json_t* rootJ) override {
  myCustomFunctionThatNeedsToAccessRootJSON(rootJ);
  Module::fromJson(rootJ);
}