Long startup time when using NeoVim

[bennyyip]

Platform:
Arch Linux
NeoVim 0.2.2
Vim 8.0.1397

vimrc:

let s:is_win = has('win32')
let $v = $HOME.(s:is_win ? '\vimfiles' : '/.vim')

call plug#begin('$v/bundle')
let g:plug_window  = 'enew'
let g:plug_pwindow = 'vertical rightbelow new'
Plug 'tweekmonster/startuptime.vim', { 'on': 'StartupTime' }
Plug 'Yggdroot/LeaderF', { 'do': './install.sh' }

call plug#end()

Problem:
LeaderF takes about 320ms to start while only 0.054ms in Vim. Most of the time used is in opening buffers.

opening buffers (319.884)~
319.755   LeaderF >
	307.832   /home/ben/.vim/bundle/LeaderF/autoload/leaderf.vim
	11.924    /home/ben/.vim/bundle/LeaderF/autoload/lfMru.vim
<

The full log is here.