.....Wonder how difficult it would be for a manufacturer to add Truarc retaining/snap ring capability to a pliers multitool? Perhaps just adding a small hole on the side of each jaw and supplying two plug in pins would work. The gear driven SOG PowerLock multitool would be a good candidate for upgrade because you can force the plier jaws open or closed under controlled pressure without the handles folding.
I think what Parnass has in mind would not be a dedicated tool, but another capability for regular multitools.Those little snap-ring tips are interchangable. (see red circle) If they could somehow be slid and locked into little holes in the plier jaws of a regular tool, they could be removed and not be in the way for regular plier-ing jobs.
... You must have to deal with snap rings a lot?