Rated 3 out of 5 stars

For me, it only works on Forwarding messages, even then, Fwd is not converted to FW, and on replies does not work at all

This review is for a previous version of the add-on (1.4). 

Hello Grey Sephiroth -

Thanks for comment. Let me answer one by one:
* I'm using it personally and many users are using it. Currently RWH doesn't work on Thunderbird 52.*, which is already shown on Mozilla about non-compability. I'm working on it, v1.5 will have support. I strongly encourage to open an issue on Github (Goto Add-on preferences -> About Tab -> Report Issue)
* "Fwd is not converted to FW" - Have you checked the checkbox on Misc Tab for this feature to work?

Please create an issue with details which can help me find an issue and fix. I hope after the fix you will revisit to this comment and provide full star :) (look forward to it)

Regards,
Jeeva