Mixing brass of the same lot number

[JFrank]

I am into F class at 600 and longer ranges. I removed the Redding button because it pulls the necks out of alignment, once i went with the carbide mandrel with a separate die, neck run out was minimized greatly. I do benchrest as well.
I liked the way the Forster button sits higher up on the stem, and wanted to see if its compatible if I were to buy the Forster stem with the button and swap it out in my Redding non bushing and bushing dies.

I don’t use either of those brand dies, but I do shoot long range ~1000 yards and mostly test and tune at 500 yards.
Things that matter at these distances are easier to identify beyond 300 yards, run out doesn’t seem to be part of the equation.
Your LR competition will most likely have case capacity / consistency on the list of importance in some order.
Jim