Can you use different fields or Custom Objects to define Hot Topics in Oracle B2C Service?

Summary:

We have recently enabled Hot Topics in one of our Oracle B2C Service instances. While the default report it generated works fine, we noticed that the subjects and threads used can sometimes not be quite descriptive enough, and might lead to incorrect or irrelevant labeling for categorizing incidents. Is there a way for Hot Topics to use either different fields or (preferably) Custom Objects of the Incidents table? We couldn't find much in the way of documentation, only that summary and threads were used to define categories within Hot Topics, at least initially.

We checked on the post linked below, where it makes mention of using Custom Objects for reporting and automation, but it's not entirely clear how it does this; the CO package provided within also doesn't seem to work (an error message mentioning the Manifest file is corrupted appears when trying to import it), and given the fact that one of these Custom Objects requires to be a parent to Incidents, we think it could potentially have major implications in operations.