It’s more about having the right equipment and then figuring out how much you’re spraying in relation to how much it expands. But it’s easy to go back and spray more or cut extra away. Just takes a lot longer if you don’t get the hang of it quickly.

If you’re going to do it yourself you might as well just do it all spray foam though. Just get a good saw to even up overspray back to the studs.

As jxn said if you’re building this tight of a house you need to figure out air exchange or you’ll get condensation and then have problems down the road