NotoSansMalayalam has the following ligature rules for ന്റ (nta)- All uses Akhand Opentype featurenotosansml-nta1

  1. uni0D7B(ൻ) + uni0D4D(്) + uni0D31(റ) => ൻ + ് + റ
  2. uni0D28(ന) + uni0D4D(്) + uni200D(ZWNJ) +uni0D31(റ) => ന്‍ + റ
  3. uni0D28(ന) + uni0D4D(്) + uni0D31(റ) => ന് +റ

notosansml-nta

The first one is what is defined in Unicode chapter 09 section 9.9[pdf]. The second is what Microsoft Kartika used to use for /nta/ as a bug. The last one is what all other fonts follows. If this is what standards can achieve, what can I say?