I keep house guns loaded one shell short in the magazine with an empty chamber, hammer cocked and safety on. The magazine is loaded with 00 buckshot, the Sidesaddle with slugs, and there's a space in the magazine in the unlikely event I need to load slug so it's first up. And yes, that means in conventional 4-round magazine 870s, there are 'only' three rounds in the magazine.
I see no need to cram every possible round in any firearm, especially tube magazine fed shotguns. If I don't fix the problem with the number of rounds available in the gun, one more round is unlikely to make any difference. Gotta learn to reload 'em, as Clint Smith says.
Mindset - Skillset - Toolset. In that order!
Attitude and skill will get you through times of no gear, better than gear will get you through times of no attitude and no skill.