I previously posted two blog posts  looking at how 「不恥」 and 「不齒」 are used as homonyms to mean “shame” in Ruan Ching-yue’s short story ‘The Conman’ (translation available here) and in A Dictionary of Maqiao by Han Shaogong (review available here), despite the former actually meaning “unashamed”. This suggested that most Taiwanese now use 「不恥」 rather than 「不齒」 , while reading 《斷代》 by writer Kuo Chiang-sheng however, I discovered a counterexample:

In this sentence, 「不齒」 is used as follows:

…展現的仍是令開放的同類不齒的無知與無奈…

… showing still the ignorance and helplessness that is such a source of shame for those gay people who are open…

The book is really good so far and I’d definitely recommend it.