Will probably get verbally abused based on this but, I was shown a little different way to do a boil and have stuck to it.

Don’t boil everything together at once.
Start with progressive amounts of seasoning instead of all at once in the beginning.
Boil the items that take the longest to cook first and put in a cooler as you go.
Boil the shrimp, crawfish, crab legs or whatever last. Going back to the progressive seasoning. You can make the first batch of crawfish or whatever more mild. Last batch you can turn up the heat to whatever you want.
Not only progressively add seasoning but after the individual batches, you should replenish the butter, garlic and sliced lemons as well.

When you do it this way all the food stays warm in the cooler and cooks the right amount time and you can adjust the seasoning/heat as you go.