I had real bad feeding issues with folded 3" euro shells out of my G2. Rolled where a bit better on the euro hulls but still not acceptable. I bought a flat of AA-HS 3" 8.5 lead. Shot some up patterning for doves and then clays. Loaded those hulls up on the 4/8tss, 1/8 steel duplex and have not had a hickup since. Two seasons in the swamps and also in Texas...from 70degrees down to 16 degrees. Smashes ducks. I actually shoot the 410 better than the 28 over decoys.
With that being said....I think the issue with the ribbed euro hulls is the taper on the end for the 3" hulls. I would bet that a nicely crimped hull that was run through a GAEP finisher would run just fine. I don't have one and the AA-HS work so I haven't tried.
Also I'll mention that you really have to look at the length of 3" hulls. Some are much longer than others and some are just way shorter than 3". I have a bunch of Rio 3" hulls that are more like 2 3/4" won't work in a MEC unless you do major press adjustments. They would work fine if you rolled them. I'd say if you were dead set on shooting new Cheddite or Fiocchi primed hulls you'll need to experiment with your machine and get it set precisely for one load and don't ever touch it again. Or, go the fold and GAEP finishing crimp route.
After talking with you and others, I’m about to give up on the 3” .410 Hulls and stick to 2.5” or maybe even 2.75” loadings. Im sending in 3 guns in .410 to be polished up and reamed for easier loading. The cheaper Turkish guns have been very picky once 3” .410 Hulls load to the brass with the reloads I’ve done.
Thanks for the help along the way. I’ll update how they function after I get the barrels reamed.