These not separated by two versions of the Unicode standards.

But I agree with you one one point – by prescribing the sequence it has, for the nta sequence, the Unicode consortium has set a very bad precedent. But that is not end of the world. Or Malayalam language.

Fonts and rendering systems can continue to be unicode compliant, without in anyway causing damage to the language. And the UTC does not encode the language, what does, is to provide a frame work for representation of the script.

Kindly understand that a “character” in Unicode sense is not the same thing as a “character” in the linguistic sense.

For example, a “character” in the linguistic sense, is a whole representation of a particular alphabet in the script; but unicode has, in several cases, used multiple (unicode) characters to represent a single (linguistic) character; and a “half” (linguistic) character does find place in the unicode’s character repertoire. Unless you recognise this difference, you will be looking at the chillu issue through a stained glass.