I think, the time of a test step execution is already exported in the execution0.log file.
Please have a look at my previous post:
Under the <projectDir>/Reports/yyyyMMdd_hhmmss/<TestSuiteName>/yyyyMMdd_hhmmss folder, you will find execution0.log file. In the file Katalon Studio stores all of the detail information about how your test was executed.
You need to develop a code which digests the execution0.log file and generate output in the format you like. There is no “out of box solution” for you.
By the way @grylion54 advised you that you can find a file yyyyMMdd_hhmmss.csv file. It is the artifact compiled by the Basic Report plugin out of the execution0.log file. You can use the csv file as is, but you would have no chance to “customize” it.