Great points!
I would also worry about survivability with trying this. Off the top of my head, efficient ways to kill a nearby nest if it doesn't activate early in the turn are:
Manos shot (gives stagger as well, so rest of the turn you can take your time), + archie charge/flurry.
Grave golem hurl corpse + reva charge + reva attack.
Seamus one shots (with focus)
And each of those sequences effectively neutralises it on the first activation (stagger, engagement, and just killing it).
So it can be taken off the table pretty quickly/efficiently, and that's not counting all the things that can make it irrelevant (staggered on a willpower attack seems particularly brutal, but also summons, etc).
I've not seen it in practice, of course. Until now I had just assumed your first few activations had to include the nests or they get neutralised quickly.