I would put my money on that the white smoke is engine oil which due to the unnatural abrupt motion and attitude has been pushed into the exhaust via the vent-pipe from the oil reservoir, and that creates a lot of white smoke, and it would be temporary.
That's where my money is too and I'm not sure what people are suggesting will happen if you pull more than the rated power - i.e. what the smoke will actually be caused by? Engine certification is pretty stringent, and 3 seconds pulling a bit more than the RFM allows is not going to result in any external visual effects (
https://www.ecfr.gov/current/title-1...pter-C/part-33).
White smoke from an exhaust is either oil or unburned fuel, and I very much doubt the latter.