vfs.zfs.l2arc_noprefetch settings in tunables

[pizzathehunt]

For older FreeNAS version the parameter vfs.zfs.l2arc_noprefetch must be set before importing the zfs pool (rc.local in tubables). Can vfs.zfs.l2arc_noprefetch set "on-the-fly" for FreeNAS 11.2 or 11.3 (Sysctl in tunables)?