I checked my IRC 2000 and it does not prohibit drilling small holes all the way up the center of a stud.Usually what I have seen when dealing with TJI or floor joist is take the size of the hole you're drilling and double it from the edge of one hole to the next. So a 1/2" hole would need 1" from the edge of the first hole to the next. I have read many articles from our local building inspectors when wiring houses.
Very true. Issues of workmanship can still be made an issue if the inspector chooses however.So, what I get from this is that codes do not address every conceivable situation if they are unlikely to occur.