This article in The Hindu talks about the issues:
Touching upon the transcribing of Tamil in Telugu script, an excerpt from the 14-page proposal reads, “Both these problems were resolved by the wholesale importation of these two Tamil consonants and simply treating them as if they were Telugu consonants. Using this hybrid orthography, the original Tamil phonetic realisation of the source text was appropriately preserved in the Telugu script without any loss.”
However, the proposal has ruffled feathers among both the Telugu and Tamil-speaking people. Several twitter handles opposed the move, stating that these characters must not be ‘imposed’ on Telugu-speaking people.
In Hyderabad, Prof Vasudev Varma from International Institute of Information Technology – Hyderabad, whose research areas include semantic search, and has been working on Telugu in cyberspace, said, “a controversial proposal. Wish such proposals discussed widely involving all stake holders. Speakers of both languages seem unhappy.”
Veeven, a Telugu technology enthusiast, who has developed Telugu digital tools, opined that on several occasions in the past Telugu characters have been encoded. The proposal mentions this, he added.
Mr Rajan, however, pointed out that the proposal to add the two characters was to only preserve religious texts digitally. He maintained that the Telugu equivalents of these characters were either not well known or were out of use for centuries.