I have Mod/Imp Mod in my clays gun and have them in for a good decade. My league guns have Mod/Full as that is how they came from the factory. Near, far, or in between those are what I shoot. The center of the pattern is the same size no matter the choke and if you center the target it doesn't matter what you use.
I shoot the same gun and chokes for trap most of the time. I shot LT Mod for 16 yard singles for a bit as that was my choice for the first target of doubles when I started out. Now, it is Mod/Imp Mod for that too. Full does make better ink balls but that would mean finding and changing chokes. Imp Mod does well enough for me, even out to the back fence. I would probably do better with Full and a full ounce and an eighth of shot but I am shooting recreationally now and prefer to keep my loadings simple.
In the 12 ga I shoot either 7/8 oz of 8s or 1 oz of 7.5s for all clay games. I try to use 7.5 on long, edge on targets and rabbits but don't obsess on it. From the 16 yard line I would have no issues using 9s if that is all I had. If buying off the shelf, buy whatever is cheap in 8, 7.5, or 9 and have fun. You are going to handicap your equipment much more than your equipment will handicap you.
