Not good for sporadic usage of reflowing Rated 3 out of 5 stars
Toggling word wrap makes it easier to avoid reflowing text in Thunderbird composition window. It is a shortcut to reset/set the option "wrap plain text messages at xxx characters". However, people who usually keep that value at 0 (or 999) and sporadically would like to reflow text, will still have to go through the long way, as there is no way to set it to disabled by default. That is for version 1.0.
This extension doesn't help wrapping a part of text while still leaving some long lines in another paragraph.
Perhaps if edit/rewrap worked in all cases this extension would not be necessary.