Call me old-fashioned (OK, your'e old-fashioned...) but set the first stop alt. Distraction can work both ways, and the VNAV step to the next alt COULD happen even if ATC said 'maintain 4000 due traffic' if you were distracted and didn't reset the MCP. It comes down to who is actually 'in charge' of this beast, doesn't it - HAL or pilot?