The new additions to the tanks dlc are all great, a very good job. The only two bugs I noticed in the dev branch are some bugs involving the physics of the tanks. I had to occasions that might be linked to the same bug:
One time, I was driving a slammer backwards and bottom of the tank hooked on a tree, resulting in the tank flying upwards like a rocket.
While driving the Lynx, Scrapping the bottom on a rock made it instantly explode.
And a few other minor sporadic jumping when scraping the hull on something.
It seems like whenever the tank is mostly making contact with the hull rather than the tracks these weird things happen. I haven't been able to replicate on demand.
