Great to see a test pkg for the m1 ready to go when I woke up this morning! So first impressions:
Install went well, on my m1 Air 8GB, approved the kernel extension as required. Reinstalling over the top caused a crash as expected. Followed the kernel tidy up instructions as given, then reauthorised the extension by manual loading it and everything went as expected.
Had to update my PATH, to include /usr/local/zfs/bin
Created new pool without difficulty
Created both normal and encrypted filesystems on the new pool
Copied 4GB to the encrypted filesystem without difficulty.
Further tinkering to come, as time permits
Many thanks for all your hard work to get us to this stage. Absolutely wonderful!