Ouch! The Piper technique may give an extra shove upwards on rotation, but loading the nose leg like that is asking for future big trouble.
I haven't flown a DR400 for some time, but I was taught at Sywell back in the mists of time by Andre Baldet to start with the stick back and then relax the back pressure.
I'm probably way out on both counts, and have caused lots of damage as I went along.
I haven't seen a PA28 POH for years, and would be very interested if the hold it down technique is in there.
SND