Never had nothing stamped in my logbook or knew there was even a requirement. Didn't have any issues with TC getting any of my licence's or Ratings I think this may be some flight school blowing smoke up your ass.
Can someone post a link to the section of the CARS that deals with Stamps in logbooks???? Or any link that states you need to take off or land at a certified airstrip with a FTU and land at one with FTU with said stamp.