Metal flatpicks with holes in them? Nope. Never seen such a thing.

I stick with the Dunlop .73's on mandolin and guitar these days. And they must be yellow.

I've gone as high as 1.14 mm. But those heavies tend to dig into the strings and get dropped which makes for an unmusical moment, and they don't sound that great.

Less than .73 has too much flex. .73 has just enough for a little give and take. (I do play fairly hard). They ring nicer and feel better.

W-O