I noticed that the grinding balls use the gem cast. But I think they should use the pan cast because they round and not "gem molded".

And this should be used instead.

The reason the gem cast was chosen was because otherwise you would not be able to have any pan made from enderio metals

And how would you build a pan from our alloys if you got balls from casting the pan?

Stupid me. :D
I don't thought about that.

But wasn't there a ball cast in previous verions of TiC?

Not that im aware of

Unless some mod added it, no.