Rated 4 out of 5 stars

I also found out, that in the latest beta version no accounts will be shown pressing the button reply and forward although these fields are marked in the settings of IC.

This review is for a previous version of the add-on (2.0).  This user has a previous review of this add-on.

You might be affected by this issue:
https://github.com/speedball2001/identitychooser-mx/issues/12

Identity Chooser 2 currently does not enhance the reply/forward buttons in the main toolbar. Only in the message header.