The altitude is set before the descend to the altitude in the MCP for which the ATC clearance was made. In offline mode you can set the height, which stands on the charts at the FAF / FAP. Here begins the final approach, for a VNAV controlled approach then before, inbound to the FAF / FAP set the DA, for an ILS controlled approach one need not set a lower altitude, as one of the active GS mode quasi independently descendants. Here then in the course of the final approach, the height is set for the missed approach, with some airlines really set 00000, but this is a company procedure. But nice that it works now at least.