Rated 5 out of 5 stars

It seems fine. However it lacks the management of "Reply all". So, for example in my case where I want to have only icons in the toolbar, I have them for all of them except for "Reply All" where there is the icon+the string.
Beside, I would like to know if it is going to support Mailredirect extension as soon as it will be ported to TB 78.x. Tnx

This review is for a previous version of the add-on (2.0.7). 

The first goal of this extension is to reproduce TB68 functionalities. So, customizing for each button is next step.

Buttons added by other add-ons are already supported.