It took me a while to understand why I have a step with Repeat Parameters (script), that does not shown in the step status after build completed.
If Step has Repeat Parameters script that returns a list of params, the step status is shown at the end, but I would have expected to see
a step status such as "skipped" or "not executed" if the Step has Repeat Parameters script that returned an empty list, such as:

${groovy:
buildModes = "";
if (params.get("TestParameters").matches(".*ARCSound@Debug.*")) {
 buildModes += "debug,";
\}
if (params.get("TestParameters").matches(".*ARCSound@Release.*")) {
 buildModes += "release,";
\}
logger.warn("Build Modes = " + buildModes);
 return buildModes;
}

Only after I added the logger.warn I saw that buildModes was empty, but it is not understood from the step status - where the step is simply missing.