Bottom-line, R’ Hershel Schachter says to wear them in.
To quote:
Chacham Ovadia [Yosef] writes that Hashem should forgive our brothers, the Ashkenazim, for wearing their tzitzis out because al pi Kabbalah, you’re not supposed to…
The Torah says “ur’isem oso,” so we assume you’re supposed to see the tzitzis. [But] Rav Gustman, who was a member of Rav Chaim Ozer’s beis din in Vilna, told his talmidim that he saw the Chofetz Chaim – who came to discuss political issues with Rav Chaim Ozer – without his tzitzis out. Rav Gustman said to him, “In the Mishnah Berurah, you wrote you have to have the tzitzis out.”
The Chofetz Chaim replied, “I beg your pardon, it doesn’t say that.” He said what he meant was that if you’re embarrassed because of non-Jews, you shouldn’t hide the tzitzis. But he said he doesn’t think there’s a din you have the have the tzitzis exposed.
Etc…
