Programmatic Creation of Subscription Order Item

Our membership organization has a somewhat complex dues system, so I have a custom form that selects the correct product variation and field data for our dues payments. This has been working fine.

Now I would like to expand to using recurring... Is there any additional magic that I will need to do beyond the plain vanilla below?

 $order_item_option_1 = $cart_manager->addEntity($cart, $product_variation);