The best way to know about any new shot, and gun is to pattern the load and the shot on paper. Have you done that??
Since NO TWO guns shoot exactly alike, and you don't indicate if your gun is choked, you are asking for a lot of people to guess about a lot of factors.
How close do you expect to get the ducks or geese to you before you shoot? Do you know what the range of your shotgun is with black Powder, and steel shot of any kind?
If your gun is choked, what choke are you using? Have you tested other choke diameters in the gun with this new shot?
I hear of lots of new hunters using these duplex loads, but don't know any older, more experienced shooters who use them.HINT! They work in some situations out of some guns, but are not a universally pattern producer. If they were, No hunter would load anything but duplex shot loads for hunting. HINT!
I think #2 steel shot is large enough for Ducks, out to maybe 30 yards in a modified choke barrel, FWIW, but I don't think I would want to be shooting ducks with any larger shot, and certainly not the big shot with the rims around each pellet that you describe. I really like duck, and want something left to eat! I think #2 shot, conversely is a bit small for Canada geese. You don't really give the size of the rimmed pellets.
You need special plastic wads to shoot steel shot in a Mler shotgun, and that means you also need a good plastic solvent( or Acetone) to dissolve the plastic in the bore, and then a black Powder cleaner to get the BP residue out of the gun. Sounds to me like more work than just using a straight load of some shot size, steel, or osme other non-toxic shot, for hunting ducks and geese.
You can make up thick walled paper shotcups to protect the barrel, from the lead, and avoid the problems associated with using the special Plastic shotcups available for modern gunners.