Recently, we proposed a node-based framework that can be used to simulate large circuits of nonlinear photonic components both in the time-domain and in the frequency-domain. In that framework, components are described using a flexible and very general 'node'-definition, allowing to simulate circuits that contain a wide variety of components with different physical effects. In this paper, we extend the node-definition of this framework such that the linear coupling between access waveguides and resonance states in optical resonators can be more explicitly incorporated, reducing the simulation time in large-scale cavity circuits.