I used an eotech on my shotgun for a couple of years. I really like eotech for the large site picture, they are rugged and just plain work. However, they sit a tad high for a shotgun, even with a cheek riser, they still work fine but there are more ergonomic choices out there.
I started the sighting in process with slugs, then switched to predator choke with 4buck at 20 yards just to get a POI reference. Shotgun chokes and accuracy are a quirky thing and a lot is trial and error.