To extend the service-oriented architecture to support other zk-SNARK toolkits beyond ZoKrates, a modular approach can be taken. By abstracting the specific functionalities of ZoKrates into generic components, the architecture can be made adaptable to different zk-SNARK toolkits. This involves creating standardized interfaces for circuit execution, proof generation, and interaction with the verifier contract. Each zk-SNARK toolkit can then implement these interfaces, allowing the proving service to seamlessly integrate with various toolkits. Additionally, a plugin system can be developed to dynamically load and utilize different zk-SNARK implementations based on user requirements, further enhancing the architecture's flexibility.