I agree with you. In all Kannada boards, it can be changed to Dandu, but English name can continue as Cantonment itself.
In Tamilnadu, all junctions have the Tamil boards as 'Sandippu' -- சந்திப்பு -- like Salem junction as -- சேலம் சந்திப்பு. I am unable to remember/ recollect any similar name in Kannada for 'Junction'. Can you help?