already said many times, HPF is one of the process used to form Ultra highstrength steel parts from using lower strength steel sheets and it doesnt mean if dont use HPF means no ultra high strength steel found in the car,
there are many ways to form Ultra high strength steel . you can also start with using ultra high strength steel sheets to begin with.
at the end of the day, how strong your car is, you have to test it and see if it complies with global standards and get what rating for what tests
simple. not just looking at a bunch of parts found in some section of the car