Since the import of ZFS on Linux OpenZFS, identification of VDEVs not using native block size was omitted. This is a regression.
NAME STATE READ WRITE CKSUM
dsk02 ONLINE 0 0 0
mirror-0 ONLINE 0 0 0 ada1s4a ONLINE 0 0 0 ada2s4a ONLINE 0 0 0 block size: 512B configured, 4096B native
This patch resolves the regression. The code was copied from FreeBSD 12-STABLE.
A pull request is in progress