You can read arrow keys as well as other keys without any unusual commands; you just need to conditionally add a second read
call:
escape_char=$(printf "\u1b")
read -rsn1 mode # get 1 character
if [[ $mode == $escape_char ]]; then
read -rsn2 mode # read 2 more chars
fi
case $mode in
'q') echo QUITTING ; exit ;;
'[A') echo UP ;;
'[B') echo DN ;;
'[D') echo LEFT ;;
'[C') echo RIGHT ;;
*) >&2 echo 'ERR bad input'; return ;;
esac