Many Mark III owners have found that spent cases get "tripped" and turned sideways, case mouth pointing outward, so they stove-pipe between the bolt face and the front edge of the receiver port due to hitting the metal tab on the front end of the LCI before hitting the ejector, so they'll remove the LCI completely and either leave it open or install a filler. No more stove-pipes thereafter.
I use dry wall anchors as "snap-caps" to relax the compression of the hammer spring in my Ruger Mark pistols, so with a snap-cap installed the LCI gives a false positive that the pistol is loaded.