Back to the question of how to spell Leib.
I spoke with a posek in town who happens to be named after R' Leib Malin. He told me that there are stiras in how R' Leib spelled his name.
With regards to psak, he told me that the accepted position here in Yerushalayim is that of R' Yosef Cohen (
https://tinyurl.com/y3skcd3y , father of current Chevron Rosh Yeshiva, R' Dovid Cohen) who paskend for Gittin that Litvish spell with one Yud, while Chassidim spell with two. Similar to the psak of R' Yosef Fleishman I cited above.
I mentioned that R' Chaim Stuchiner spelled with 2 yuds, but I subsequently found his wedding invitation where it was spelled with one. So it seems he did both throughout his lifetime.
Bottom line - it's clear to me that there is no universal "correct" way of spelling Yiddish names.