Tried, don't like. Ruins the ambidextrous capabilities of the gun.
I'm left handed and shoot it left handed most of the time, but the corner just outside my bedroom down my main hallway is a right-hand turn.
As such I run side-saddles, but I'm running a Stevens clone of the Ithaca and have left and right saddles since it ejects out the bottom. Don't have any SxS or O/U scatterguns.
Defensive use, or hunting only?
If hunting, I've tried the Uncle Mike's elastic sidesaddle and I liked it well enough strong-side-only, even though it was intended as a right handed installation and I rotated it around the gun for a wonky lefty install. I took it off when I realized I didn't like the effect of 12ga shells on my cheek during recoil.