This is true. The only thing I change when hunting Merriams is to take a high pitched box for the long distant calling that often comes with the Merriams terrain.
^^^^^
This.
I have a purpleheart/purpleheart short box I like. And for a production call, the FoxPro with the hole in the bottom (I have it stored away. But it's Rude Snood or something similar to that) is high pitched and will REALLY reach out and touch their ears.