Yes. Rolls used it as an engine test bed. Remarkably fast machine.
In a letter to Heinkel, written after seeing the aircraft perform with the Rolls Royce Kestrel engine fitted, R. J. Mitchell said:
We, at Supermarine Aviation, were particularly impressed, since we have been unable to achieve such smooth lines in the aircraft that we entered for the Schneider Trophy Races....
In addition to this, we recently investigated the effect that installing certain new British fighter engines would have on the He 70, We were dismayed to find that your new aircraft, despite its larger measurements, is appreciably faster than our fighters. It is indeed a triumph.