Multiple thermostat automation

I have two Nest thermostats that depand on a single boiler. Only Nest A can actually turn the boiler on (steam heat). Nest B is hooked up to a water circulating pump. (It cycles the water used to generate steam.)

What I’d like to do is circulate the initial heat then then the residual heat after the boiler turns on/off.

Basically:
After Nest A turns on, wait 10 min then turn on Nest 2 for 15 min.
Also:
When Nest A turns off turn on Nest 2 for 15 min.

Core or WebCore with NST Manager or My Next Manager should be able to do this w/o issue, although Nest thermostats do some of this already.

You would think, but there is no way to do this with native app