CZ 805 Bren Upgrades

This is an older rifle that has worked reliable forever. But I’m wanting higher rps and I don’t care about fps (to an extent, just can’t be stupid low).

I’m planning on upgrading to a high speed + torque motor, the piston to full aluminum, gears to 13:1 ratio, trigger (speed trigger), mosfet (Gate v3), hop up, cylinder head, and piston head.

What upgrades have you done to your Bren or your V3 gear box that you’d recommend?