I just completed stubbing in all stratum_v1 rpc handlers. These sit on the same base as electrum, so they everything is fully functional apart from populating the responses. Currently they all send error::not_implemented, eg:
bool protocol_stratum_v1::handle_mining_subscribe(const code& ec,
rpc_interface::mining_subscribe, const std::string& user_agent,
double extranonce1_size) NOEXCEPT
{
if (stopped(ec)) return false;
send_code(error::not_implemented);
return true;
}