It would be a real improvement if a concrete trace could also be extracted from a xtr trace file.
With the information found in the XTR file, this is difficult to achieve without the machinery found in the UPPAAL engine. As a first step, I have added support to verifyta for generating pre-stable traces. This might make it easier to hack concrete trace printing into the tracer utility, but a more permanent solution is to extend/replace the XTR file format with a more self-contained format better suited to the task. However, this will not happen before 3.6 is released.