Years back I bought an 870 wingmaster to take my first shotgun class and one of my class mates used this HD Apron. Kept birdshot on left and slug on right could reload easily while not shooting, worked pretty well. When going prone shell naturally moved out of the way, although my first prone was on a fire ant mound....Not pretty.
Also worked with transitions to pistol as apron was under holster and didn't snag. An odd option for sure, but still use for pistol classes to reload mags while waiting around.
https://www.homedepot.com/p/The-Home...5-TH/310338162