Ответ 1
От :help ttimeout:
'timeout' 'to' 'notimeout' 'noto'
'timeout' 'to' boolean (default on)
global
*'ttimeout'* *'nottimeout'*
'ttimeout' boolean (default off)
global
{not in Vi}
These two options together determine the behavior when part of a
mapped key sequence or keyboard code has been received:
'timeout' 'ttimeout' action
off off do not time out
on on or off time out on :mappings and key codes
off on time out on key codes
If both options are off, Vim will wait until either the complete
mapping or key sequence has been received, or it is clear that there
is no mapping or key sequence for the received characters. For
example: if you have mapped "vl" and Vim has received 'v', the next
character is needed to see if the 'v' is followed by an 'l'.
When one of the options is on, Vim will wait for about 1 second for
the next character to arrive. After that the already received
characters are interpreted as single characters. The waiting time can
be changed with the 'timeoutlen' option.
On slow terminals or very busy systems timing out may cause
malfunctioning cursor keys. If both options are off, Vim waits
forever after an entered <Esc> if there are key codes that start
with <Esc>. You will have to type <Esc> twice. If you do not have
problems with key codes, but would like to have :mapped key
sequences not timing out in 1 second, set the 'ttimeout' option and
reset the 'timeout' option.
NOTE: 'ttimeout' is reset when 'compatible' is set.
Из комментариев:
В принципе, ESC является "лидером" для стрелок и других управляющих последовательностей, поэтому вам может потребоваться дважды нажать ESC, а не один раз. - @Антон Коваленко
Запуск
set notimeoutиset ttimeoutрешил мои проблемы. - @nightcracker