5 つ星中 5つの評価を受けています

I assume the add-on works just fine, but before installing it, a simple question - why does it need a permission to "Have full, unrestricted access to Thunderbird, and your computer"? What does it mean?

これは以前のバージョン (2.16) についてのレビューです。 

With TB78 the extension system changed towards MailExtensions which only allow access to TB via a subset of APIs. Those APIs are currently not enough to build TbSync. I therfore use a special API which gives me full access like I had with legacy extensions in TB68.