I’m doing a whole-house renovation (100 yr old brick home in Zone 5) and have supplemented the original steam boiler system with a dual-zone Mitsubishi system (one SVZ blower per floor). The first floor system is in a semi-conditioned basement while the second floor system is in the unconditioned attic. The Mitsubishi system will use MHK2 wireless thermostats, and the original boiler and steam radiators remain in place to handle primary heating load on winter days.

I had assumed my installer would integrate the boiler to the Mitsubishi system using a Kumo Station controller along with Kumo Cloud as per this application note:
http://mylinkdrive.com/viewPdf?srcUrl=http://s3.amazonaws.com/enter.mehvac.com/DAMRoot/Original/10006%5CApplication%20Note%203054%20ME%20-%20Kumo%20Station%20Application%20Guide.pdf

… and then from there I’d set up the boiler as backup heat, set the min outside temp for the heat pump to something reasonable, and then let the Kumo system run the boiler as needed. For some reason, my installer said I need to just run the boiler on its own thermostat. There’s a bit of telephoning going on with my GC, but they say they made multiple calls to Mitsubishi and there was no way to integrate the boiler into the Kumo system and that attempting to do so would cause all kinds of problems with the systems competing against each other. This makes no sense to me given the above application note and the entire point of the system.

In any case, I could understand if the rationale was that the Kumo system wasn’t very good/reliable at controlling external boilers vs., say, an Ecobee. I was using an Ecobee with multiple temperature sensors prior, and it was indeed very effective at managing the boiler. However I’d really like the two systems to work in tandem as Mitsubishi purports to allow. My plan was to have the boiler back up the upstairs system and set the cutoff temperature for the heat pump on the high side (e.g. 32F) to prevent losses/ice damming in the attic, effectively letting the boiler heat the entire house on cold days and rendering the downstairs heat pump as backup heat (there are a couple rooms that lack radiators and would benefit from some cycling of the heat pump). 

Anybody have a dual-fuel Kumo Station setup they’re happy (or frustrated) with? Should I just keep separate thermostats as my installer recommends, or attempt the Kumo integration?