Supposedly, the license is written to the RAM and cannot be removed even if the ECU is reverted to Ecutek stock. This being the case, when the stock ROM is pulled before tuning, the license is still in place. So in theory, the license is still valid as long as the original ROM is still present. Once you write a different revision over what was licensed...all bets are off.

This was what I got from talking to Ben @ Ecutek North America.