I know that the pkg(5) team is interested in generic Python bindings for SMF, and I'd bet that the SMF team is as well. At least, those I've talked to are. You should probably get this reviewed on smf-discuss; it may be a private interface now, but a) they may be able to find more severe mistakes than folks on this alias, and b) they may be able to point you towards design decisions that will make it easier to increase the commitment level of the interfaces.
Danek