I built/installed from the latest source as of today and allowed OpenZFS to upgrade my pool (probably a bad idea) anyhow, ever since then I'm showing kernel_task using around 7GB of ram (about double what it used to) and over the last few hours it's written about 41GB to disk (the computer has been sitting idle this whole time with nothing running on it). Also eventually IO tasks to the zpool start hanging for very long periods of time, occasionally indefinitely.
I have re-disabled spotlight on the volume so that's not it. Any ideas?