The "Call steps from another test" feature works well for testing a matrix of parameter values. However it doesn't allow for passing in static, never changing values to called tests for the sole purpose of re-usable script steps and provide a single point of change (aka single point of maintenance).

For example:
* You have an portal based site which has several "apps" or sub-sites.
* When a user logs into the portal the get presented with a dashboard page with links to each of apps.

Ideally the tester would be able to create a single login script that can be called from other scripts passing in the UID, PWD, and destination app. The parent or "calling" script in this case would always use the same destination, and may or may not use the same credentials.

Another example:
* You have a process that can be completed once successfully, but if you attempt it a second time the user should be thwarted and an error message should be displayed.

In this case the ideal approach for the tester would be to call the same script with the repetitive steps twice specifying a different desired outcome for each called instance.

Even better would be for the called script, which may have numerous parameters, be able to be used with this parent script as well as others. In this case the tester would want to be able to statically set some if not all of these parameters depending on the intent of the parent test.

These situations do not need to, nor should, have the parameter values set at a Test Instance level since they are not relative to the parent test being run various ways or using different data sets etc. The parent test has a static purpose, but the tester wants to enjoy script step re-use and have a single point of change when the site is changed.