Hello Peter,
For some reason, it seems that Thunderbird 52.0 can be installed with Thunderbird menu "?/About Thunderbird" although it is not officially available on Thunderbird web site.
BirdieSync
3.1.0.0 beta 1 has been released which supports Thunderbird 52.0. Due to important changes in Mozilla core technology on which Thunderbird is based, it was necessary to fully rewrite BirdieSync add-on in Thunderbird.
Although this new add-on was heavily tested, it is highly recommended to
backup your data.
For more security, the preview of operations to be performed during synchronization was enabled again.
Feel free to report any problem you could have with this new version.
Thanks.