You can experiment without routing.
Remove the pickup from the body and hold it on the other side of the strings. Rig up some spacers to give the correct string height, and move it around (or have someone else move it) while you play it.
You'll know how it will sound, and you'll know exactly where you'll want to put it.
It's a PITA, but beats Russian Roulette.
I love this.
What a great idea !!