No, it will still protrude.
Not sure who Gear Expert, Tom B. is, but his answer is incorrect. I just installed this DPM reduced recoil spring system on my Hellcat. If the question addresses this particular fitment, yes it fits flush, does NOT protrude beyond the muzzle end of the slide and should work with a myriad of comps. This kit comes with a bushing/spacer adapter that takes up the difference in size between the bored hole for the factory recoil spring and the outer diameter of the external spring’s guide rod. I took photos but cannot post them here (so it seems). Hope Tom’s answer didn’t deter you from getting the comp you want.
It does not protrude