Connection stalled in multithreaded app with 1.6.x branch

Hi,

I have 5 Python 3 processes, each running 2 threads.
Each process has an MQTT connection shared by the 2 threads.
After a random time some threads are stalled with wait_for_publish method.
My understanding is that you're working on supporting multithreading in 1.6.x branch but apparently it is not yet there.
Currently, only working workaround is to not use wait_for_publish but rather use a loop to wait with a timeout. If the timeout is reached, we disconnect and then reconnect.
Do you have some update to share, and maybe a release date?
Many thanks in advance.

Best regards,

Cyril