TestStand provides built-in functionality for managing properties such as test limits. This can be accessed either from a dialog box or programmatically in a sequence as a special step type.
The properties and limits can be stored either in a file on the machine or in a database. The file approach, while simple, does have the caveats you mentioned, where file versioning would be important. This could be mitigated by storing the property file on a shared network drive.
Using a database for properties would likely be more adaptable to change. By storing the properties in a single location accessible by all test machines, you can easily update the values in one place and have them propagate to different testers.
In either case, you would load the properties into the current TestStand sequence either interactively through the Import/Export Properties dialog box or with a Property Loader step at the beginning of your sequence.