kevf7. The followers are very similar to the plastic mags followers just opposite in cartridge stagger.
On my old waffles I removed 3/32" off the top of the nub that trips the bolt holdopen on the last round.
Wait till you get your mags and try them with 2-3 rounds. Maybe yours won't need trimmed. Mine was trying to lock back with 1 round left in the mag
I have a few SR25 20's that work fine and needed nothing.