Rev-x has been shown time and time again help injector stiction.
If you have ever been inside any engine and saw the brown film on internal parts, that is what is causing the stiction. That film is on the injector plunger, making the plunger stick. As the truck warms up this film will "melt" (for lack of better description) and the injector will run normally. The Rev-x is used to clean that film off/make the film "slippery" allowing the injector to function as designed. A "band-aid" approach? Maybe, but my opinion is that if it works, why not?
Not to "knock" Rev-X, although IMO it's just another oil additive, fix all, grow new metal to worn parts etc... But
The injector plunger doesn't operate in lube oil hence doesn't develop the "film" you referenced hence the Rev_X doesn't clean it and isn't the cause of stiction in the HEUI's.
The stiction that creates the miss(lack of cylinder contribution) is with the shuttle(or spool) valve. The shuttle is the little metal rod that the coils draw to and fro(via the 48v pulses). The stiction(lack of smooth movement back and forth) is because the spool valve wears itself to a super smooth polished state due to movement back and forth and when the oil is cold(colder) gets harder to move. Sorta like picking up a wet glass sitting on a smooth surface.
Rev-X and the others, thin the oil making it less "tacky/sticky" and lowers the oil shear rate lessening the effect that causes the stiction.
IH was purportedly starting to use injectors with modified spool valves.
Rev-x worked/works on my truck. Another positive for stiction is I'm also running the newest flash on my FICM which helps as well. Better than injectors.
I'd second the software flash comment. One of or maybe the lastest version, operates each spool (one at a time so as to not fry the FICM as fast) to help loosen it up and make it move mo freely when you first turn the key on prior to firing up the engine.