POROs to build complex models

It sounds like you’re creating what’s often called a “form object”. You may find these articles helpful:

There’s also a Weekly Iteration Video on the topic of form objects.

Is there a clean way of doing the following that doesn’t require a method call?

I’m not sure what you’re asking here? You want to avoid calling persist! manually and would prefer just to call save ? If so, the example in the Code Climate blog post should have you covered.