Force new conversations for replies to old resolved conversations

We've asked about this briefly before, but I'm opening this discussion to discuss in detail and understand the options. Context We're a B2B company with fewer customers asking more questions than a typical B2C company that has more customers asking fewer questions. Goals To provide great service to our customers, we want to: • Distribute incoming requests amongst our customer support team • Measure the productivity of our customer support team Challenge Scenario We think this will be challenging in this scenario: 1. A customer emails us, an agent helps them, and the agent resolves the conversation 2. After a few weeks, the customer replies to the same email thread about a different issue Issues If I understand correctly, that last reply from the Customer will re-open the same already-resolved conversation. This seems like a problem in a couple ways: • The conversation will remain assigned to the previous agent, so: * If th…