RE: Precision Aerobatics Katana MD Build and Fly
yes you can line the esc up with the bottom hole of the cowl that works great. i did that only mine is way back near the firewall. (edit: i am using a castle creations 45A esc rated for 60A bursts so it tends to run very cool on a setup that draws only about 30-37 in bursts and much lower averages)
in any case, all the air forced through the cowl openning inevitably flows on and around the battery pack and continues it's way back out to the rear openning. No need to worry about this as no matter where your esc is it can't block the pack from the path of flowing air.