Notosans Bengali has interchanged two ligatures হ্ণ হ্ন about bengali

[tiroj]

The same issue was posted re. the Tiro Bangla fonts, which prompted me to revisit the question which we had referred to Bengali language experts in 2011. I caution against making this change without further research, as some important sources support the ligature mapping as it currently is in the Noto and numerous other fonts:
TiroTypeworks/Indigo#30 (comment)

[bkmks]

And the same problem with Noto Serif Bengali

[nizarsq]

[bkmks]

A further proof is the list of ligatures here:

One can see that ন (U+09A8) always comes at the bottom for all the other consonants, whereas ণ (U+09A3) always comes at the back of the consonant.

[bkmks]

Adobe fonts have got it right

[nizarsq]

@madhavkiransodum are you aware of a unicode design document for the combination you mentioned?

[bkmks]

@nizarsq No sir, I have not come across any such document regarding combinations. Unicode consortium has released only the character code tables it seems...

But there is a host of well edited literature in bengali with this right usage.. like the following: viṣa-vahnim from Haridas Das's Gopala virudavali

[bkmks]

Another write example: gṛhṇāti (from Sajjana tosani a 1872 bengali magazine)

[simoncozens]

Based on John's additional research, I'm not planning to take any action on this for now.