And many Sefardim, Yemenites, and other fine fully Torah observant Yidden have had multiple wives as recently as even after the State of Israel was founded after WWII, when they brought their multiple wives from their home countries to Eretz Yisroel.
Now even the Sefardim and Yemenites don’t take more than one wife.The Baal Shem Tov took no position on this matter.