When all is said and done...use your ear. Visualizing the fretboard is an eye and ear endeavour. So when it comes to comping in a real life setting, it should be understood that playing off of the soloist and other musicians is the key to standing out as a great rhythm guitar player. I know this concept isn't used with rock so much but it should, and I implement this all the time no matter what style. So remember to listen to your surroundings (in this case what's going on in the backing track!)
Hope this was helpful. As always, any questions be sure to hit me up in the forum. Enjoy the backing tracks on the next couple pages!