I assume that all support requests will need to go into the SmartBear support team (link below), and they'll determine if your request is something that they or another team in SmartBear can help with. Another workaround option I didn't mention is the Bulk Edit feature: you could create a new custom field that is correctly configured, then batch up your test cases for edit (using the Filter feature if required) and populate the new custom fields. This might not be manageable given the size of your project, but I wanted to give you all options I can think of (and someone else might stumble upon this post and find it useful one day 🙂)
SmartBear Support