Nom, it’s true that rav belsky held that the shavers the litvishe world uses were perfectly kosher, but many of his talmidim, including me, were strict, and he held that using trimmers instead was a good chumra to practice. He said that even lift and cut should be ok, because he said it’s a marketing gimmick, but that he cannot in good conscience allow something which claims to do what it says it does, so he said that the mechanism must be removed.
He also held it was a significant inyan for even bochurim to have beards(of any length; this wasn’t a kabalah issue, but rather part of how the chofetz chaim describes as the tzurah of a yid), and indeed having a beard is more common in his Yeshiva than elsewhere.