Hello Franz,
indeed, the standard pace I use with my chess computers is 15secs/move; therefore I used it as well for my tests based on the Spacious_Mind worksheets.
Of course results may/should change at 30s/move... as far as the resulting score is concerned. But I think the relative ranking across different settings should not change so easily.
Of course, tournament time control could tell another story...
Warm regards,
Eric