I was extremely disappointed to find that it is not possible to set or alter core or user dataset properties from a ZCP. My use case is to keep track of snapshots managed from a ZCP: identify which snapshots were taken by my program, when, and for what purpose. A lua function such as zfs.sync.set_prop(Dataset, Property, Value) mirroring the effect of the "zfs set" command would permit me to safely manage those snapshots.
zfs-devel@ is not actively used anymore. fs@ is the list.