My apologies for overlooking the other option. I do agree that having symmetry between the packages would lend itself to ease of configuration. Either way, I'm happy the option exists. Thank you. 

-------- Original message --------
From: Juri Linkov <juri@linkov.net>
Date: 3/18/20 7:58 PM (GMT-05:00)
To: No Wayman <iarchivedmywholelife@gmail.com>
Cc: emacs-devel@gnu.org
Subject: Re: Feature request: tab-line-new-button-show

> Juri very kindly added `tab-bar-new-button-show' to control the display of
> the new button in tab-bar-mode in response to a message I sent him
> on Reddit.
>
> I think an analogue variable in tab-line-mode would be great for
> keyboard-centric users of tab-line-mode.

Thanks for the feedback.  tab-line-mode definitely should allow doing the same.
Actually it already does.  When tab-line-new-tab-choice is customized to nil -
"No button".