Rules Comparison Operator Is Missing The Direct Input Method
The key to this problem was that the data comparison was actually comparing against a field belonging to an entity that was referenced to an entity that was referenced to the entity in question.  The structure was: Task -> Ticket -> Equipment: field-manufacturer.

The solution was to specifically declare the field in Rules using "Entity has field".  In this case, I was using two entity references, so I had to use "Entity has field" once to bridge to the first entity, twice to bridge to the second entity, and a third time to identify the particular field on that entity that I wanted to compare data against.

After I set the "Entity has field" conditions in place, I was able to compare data using "is one of" and it gave me a field to type in multiple TIDs.