I reckon the difference in time on the runway between a reduced thrust setting and full poke isn't all that significant. One might also argue that by accelerating more quickly, that you might smack something before it has a chance to clear the runway
I agree with Johnny, but would also like to suggest that engine failures are more likely when the engine is working harder. Has everybody seen the pix of the uncontained CF6-80A failure on an AA 767 at LAX on June 2nd? That was a high power run-up.
There is no rule or guidance in Canada that advocates such a thing. Air Canada used to do so, but changed after the CAIL merger when the logic was revisited.