The Tzanzer Rav used to do it. When he would visit Hungary, though, he wouldn’t. It wasn’t the Minhag in Hungary.
The widely practiced Shiur is very inflated. Besides, there are many who have Mesoros from before the Chazon Ish with a smaller Shiur. Let’s not forget that a K’zayis is not supposed to be Kidei Svia. Does it really make sense that I have to eat a whole Matza to be Yotze a K’zayis? A K’zayis is the smallest amount that is considered eaten.