The settings to link the heat and humidifier together are in the
"equipment" settings for the nest. If they are not already set up (they
should be if it is running now), then you will have to set where HVAC
components are plugged into on the Nest. On...
Best I can tell after having just done it is that, yes you can control
with the newest nest. However you have to go into the “pro” settings
under the equipment screen. Once you confirm the type of equipment for
everything you can test it all out. Of ...