Rated 2 out of 5 stars

The previous version (Show Address Only) did not require any permissions, and this one demands "full, unlimited access to Thunderbird and your computer". Is this add-on safe?

I liked the previous version (5*) but I won't install this one. I don't understand why I should give such wide authorizations... :-(

This review is for a previous version of the add-on (1.0.0). 

Currently (TB78) there is no permission-based API to modify message list layout. Only way to do it is by using Experiment API (https://thunderbird-webextensions.readthedocs.io/en/68/how-to/experiments.html), which runs without any restrictions, as it did pre-TB68. Previous version ("Show Address Only" add-on) used to run on same permission level, with full local privileges.

You shouldn't trust software downloaded from Internet or take anyone's (especially author's) word for it. The addon's source code is tiny and available at https://github.com/lkosson/full-address-column.