Safe configuration for editing pass entries

Question

So I use the Pass program to store passphrases with gpg. To edit these entries you can use the $EDITOR environment variable. Now, I had set vim to store swap files and backup files with the following commands in my .vimrc file:

set backupdir=~/.vimtmp//
set directory=~/.vimtmp//
set undodir=~/.vimtmp//

Of course this stores my pass entries in cleartext, which is bad. i have tinkered with the ideas of setting my $EDITOR variable to vim -u NONE -i NONE or just busybox vi, but I don't know what the safest alternative is, or if there's even a different vi clone meant for this kind of stuff. there's also a vim-redact-pass plugin but I'd rather not use any plugins at all to minimize risks. What's a reasonably safe way to use vi{m,} to handle pass entries?