Hi,
There are no configuration settings to modify the formatting of the data in the report like you need, you do have to use the callback function like you are doing.
You can use the ReportEntry parse and reformat as you wish; like you mentioned. You can also use the Parameters.Result, read the data from the step and create your own string. You will need to use functions to convert numbers to strings. And you will need to use the TestStand API to get the names of each of the measurements in your multiple numeric limit test.
Either option involves some work. It's not hard, it's just not fun.
Marcela.