This discussion seemed fizzle out quickly with little further discussion, so here are some out of the box thoughts comparing the perceived efficacy of shotgun trigger/safety systems vs handgun trigger/safety systems:
Even proponents of shotgun "cruiser ready", known if handgun circles as "condition 3", (hammer down - empty chamber - loaded magazine), want a safety to engage.
Note: Under the direction of W.E. Fairbain, the external thumb safety on Shanghai Municipal Police issue 1908 and 1911 pistols were deactivated in accordance with required empty chamber carry.
Mossberg's go at double action shotgun triggers were rejected as a non-solution by the LE and popular market in the 1980s, in spite of the popularity of DA revolvers and double action pistols at that time.
Trigger-blade safeties, as used on most of todays polymer frame pistols, seem to be a non-start for shotgunners who fear unintended discharge from brush or other possible snags entering the trigger guard in the field. Essentially, shotgunners consider a trigger-blade safety dangerous without some type of complete trigger cover. Apparently todays handgunners tend to agree.