I got my grommet setter last week...WOO! It works so much better than those cheap plier-like hand tools. I can't believe I didn't just cave and buy one sooner (and it came with 900s grommets and three different size dies!)
I already had begun putting grommets in the Tinkerer's Frock Coat by hand (and with a plier-tool) in a different style grommet, so I was afraid I'd have to put the rest in by hand. But SCORE! The flange width doesn't matter. The dies are based on grommet size (inside diameter) and it didn't warp the wider flange grommets! So pleased with this toy!