LB7 only uses two pulses per a power stroke. pilot and main. i think the later years that have the piezo injectors have up to five injections. as the engine progressed through the years the injector problems became less yet the number of injection cycles increased.
so it is not the number of cycles that does it
check this link out: Duramax Fuel Filter, Duramax Diesel Fuel Filter, Duramax Fuel Filter Change
it may or may not be true but another side of the story
some of those "canned" tuners will raise the rail pressure which it has been blamed on too. by the way, most EFI Live tunes dont turn off any of the injection cycles.
the problems with the injectors probably lies somewhere between injector design and fuel issues. not programming