I thought it was a good question too!
I just called and spoke to a nice gentleman who answered all my questions....thanks Brent!
The mount needs 1.5" laterally from the cutout, so that is why there needs to be 1.5" to the studs.
And it looks like I will have enough clearance to fit a W3 in the space I have. The cutout will be made very close (1/4" or so) to the pipe, which will leave enough room on the other side to clear the stud. I have 1/2" drywall, so the mount will only be approx. 1" deep from screw entry point to exit point. So that will leave about a 1/2" to the depth of the pipe. The screws are 2" long, so I will need to find shorter screws. But that is all I will need to make the W3 work for me!
