I just got my taz4 and am having the same issue with over flow/ leaking, this is the second time its done this, it’ll start the print fine but on longer prints will leak, I’m going to try and see if the tape on threads will help for now.
It’s my understanding that some of the hot ends were equipped with a section of PTFE that’s too short. If your leak is resulting in puddling on top of the heater block, you should contact support about it.
g.