On this occasion, it was not possible to incorporate importing your own samples for SPECTRES. At the moment we do not know whether it will be possible to implement this functionality in future.
However, there is a vast and varied library of source material creating endless possibilities in sound design, which we consider to be the bulk of the value. We've had users initially express concern about the lack of user sample support, but then come back to us later saying they simply don't need it!