My experience about the KO's is that I have never seen a framer line up the TGI's so that the KO's could be used in a neat and workmanship like manner. Usually staggered (because of length cutting at the lumber yards for delivery), or some tipped upside down in relation to the others. Usually end up drilling anyway. Here in Wisconsin most heating contractors prefer wiring that is installed first to be closer to the bottom of the TGI. For a smaller hole of 2", I think the books that come attached to some of the TGI's usually say within 1/2 inch of bottom support ridge (or whatever they are called). Holes must be twice the diameter appart for most requirements that I have read. On bundling, here in Wisconsin there is an adoption to the code with exclusions like AFCI for bedrooms, and for bundling of romex. Check your state codes?
