emacs slow with large threads

[Emilio Francesquini]

On Tue, Jan 22 2019, Emilio Francesquini wrote:

> You are absolutely right. It does become buffer local. Yet setting it to
> nil changes the behavior of new windows on notmuch-show-mode. I'm at a
> loss why... :) Maybe because I set it inside my .emacs? I need to study
> a bit more of elisp...

About that, forget it. It was something else changing the
behavior. Indeed I need to study more elisp. :p Sorry for the noise.

The real culprit was indeed fci-mode.