M.2 over USB 2 is a total waste. You have really fast drive combined with very low-speed and unreliable usb interface! USB3 may fix the speed but it will not fix problems rising from USB protocols.
Try with UFS2 at least, instead of ZFS. ZFS needs lots of low level access to it's drive but USB would not pass through even basic SMART data. And USB might not work well either - will TRIMs pass it? When no, bye your new drive month later. Another failed drive.
If you want that laptop or whatever it is to ACTUALLY work, replace or have somebody who knows how to replace laptop drives, replace the failed drive inside. Then install FreeBSD on proper internal drive without doing it over USB.