Have taken the real DAT before and I can say that this is semi-true. Yes you have to absolutely memorize the fact 1 inch = 2.54 cm. I still think you need to know 5240 feet in a mile, 1.6 km in a mile, US to US conversions should be known as well (pints -> gallons stuff like that). Its not true that they give you the conversion factors there might be some cases that you might need them. I absolutely did not like the fact that he mentioned that.
Why do you think every person in their breakdown of the QR mentions something about the conversions because they definitely saw 2-3 problems on their real DAT with those kinda problems.
Solution: Memorize the most important ones and forget what CHAD is saying and listen to the general population.