The last beta has now passed all tests and has been publicly released as 4.3.10. The roll-out via automatic update happens in stages over the next few weeks. A manual update through the Nuki App is always possible.
This topic will now be closed. Thank you for the participation and the provided feedback during the beta phase. 
The new Beta iteration 4.4.x has been started in parallel, thus please use following topic to report your findings and feedback: Smart Lock (4th generation) Firmware Beta 4.4.x