[NiHaoMike]

The heat pump, being a pretty big unit at 2 tons or so, will have no problems keeping up with DHW demand. (My little 1/2 ton unit easily keeps up with demand running only 3-4 hours per day on average.) So the only remaining reasons to switch to the boiler are if the heat pump breaks down, if the heat pump can't keep up with home heating demand (at which point you switch into hybrid mode if it's still above the balance point), if the incoming water gets too close to the freezing point, or if it becomes more efficient to use the boiler.

The only demand for 130F water (dishwasher) only needs a few gallons per use. As such, just warming up the boiler will significantly cut into the efficiency. The heat pump condenser has much less thermal mass (especially for a plate exchanger) so the heat pump will still be more efficient than using the heater built into the dishwasher. (Of course, it would help a lot to have the dishwasher as close to the heat pump as possible. Like put the heat pump in the basement directly below the kitchen.)