Great way to power lasers indeed, that was actually what I planned to do too until I discovered the supplier of my laser modules put some nice 5V/60A and 12V/29A supplies on the package, a chance I didn't already purchased the computer PSU at that time
By the way, did you tested and adjusted voltage of this Connexelectronics PSU prior to install it for the scanners? Mine is performing quite well, did a few gig with it already.