Scott, you should not need a booster for the track on a 12x3 layout to run your locos and a track booster does not have anything to do with programming capability. Programming is entirely a different animal and if done using Ops mode while on the main(digitrax), again you shouldn't need a booster of any kind. In the Ops Mode, there is plenty of juice for programming on the main (track power).
However, when programming on a "programming track" using Page Mode, some decoders may need a "Programming Track Booster" that will provide about 160 ma of power instead of ~60ma. Some people have needed this booster for older QSI's and I needed one for the older Tsunami.
Unless something has changed, Digitrax does not allow a read of the CV's unless you are in Page Mode. That mode is always used with a programming track and not the mainline.