There are 2 test methods that seem to like to fail for both the Tx and non tx tests. I can't seem to reproduce this after hours of running just the tests with or without logs and with reduced CPUs available. I also couldn't reproduce it running the entire test suite with and without tracing and reduced CPU or not.
I am at a point to give up and just increase the timeouts. Currently these test expect 10s to be enough to add a new node and wait for a rebalance. The rebalance wait alone waits up to 60s. It doens't seem unreasonable therefore to just increase this to 30s. If it still fails afterwards there is some other issue most likely.