fzf_preview_window pref is only for Vim, not NeoVim?

[vitaly-zdanevich]

• [x] I have fzf 0.30.0 or above
• [x] I have read through https://github.com/junegunn/fzf.vim/blob/master/README.md
• [x] I have read through https://github.com/junegunn/fzf/blob/master/README-VIM.md
• [x] I have read through the manual page of fzf (man fzf)
• [x] I have searched through the existing issues

I have this in my vimrc:

let g:fzf_preview_window = ['up,50%', 'ctrl-/']

Result: fullscreen in Vim, but not full screen in NeoVim.