U+220F N-ARY PRODUCT and U+2211 N-ARY SUMMATION should descend below the baseline, which is the convention for n-ary operators. The current glyphs would be appropriate for U+03A0 GREEK CAPITAL LETTER PI and U+03A3 GREEK CAPITAL LETTER SIGMA instead. Here they are, with ⟨R⟩ for comparison:
U+220F N-ARY PRODUCT and U+2211 N-ARY SUMMATION should descend below the baseline, which is the convention for n-ary operators. The current glyphs would be appropriate for U+03A0 GREEK CAPITAL LETTER PI and U+03A3 GREEK CAPITAL LETTER SIGMA instead. Here they are, with ⟨R⟩ for comparison: