Doubt that it will help a lot - metadata is valuable. Sometimes the fact that you are communicating with someone is as damning as the communication itself.

Unless the addon is really sneaky and confirmed by a lot of people chances are it will still be detectable by DPI. And you have the problem of the addon traversing the state firewall in the first place.

And you need secure OOB way to transport password anyway.

From what I see you need secure way to transport keys and don't minding to raise a few red flags with the authorities.

In that case just rent micro instance with any out of country cloud provider you have access to and ssh tunnel trough it.