It seems that "מלא ב" has become acceptable (though not obligatory) to express physical fullness (while "מלא" alone has broadened to be a figurative intensifier in some cases).
I learned in lashon that you don't say "מלא ב..." You just say "מלא אנשים"
למדתי בלשון שאין "ב" אחרי המילה "מלא"
Actually, to say "ב" is correct, Israelis don't use it so often so it's sometimes forgoten... (Native speaker here haha)
Hi how about mel'eat anashim (suppose it was a female noun there.) Can we use mal'e thus way