Ability to manually merge separate support threads (chat and email) into one unified conversation

I want the ability to manually merge separate support threads, specifically a chat conversation and an email thread, into a single unified conversation within the support inbox. This is needed when a customer contacts support through different channels (e.g., starting a chat and then sending an email) for the same issue, and the threads are not automatically merged. The current workaround of manually closing one and continuing in the other is inefficient.