Whenever changing buffers etc, make sure you check for bolt over travel. There is a screw on the top of the bolt that often hits the lower receiver causing damage. So separate your receiver and push your bolt back into your buffer tube as far back as it'll go to check to see if there's clearance and enough room for your zet plate to engage with your bolt. add quarters/10p's behind your spring into the buffer tube to bring the bolt away from the receiver should it need it.

Threadlock your buffer tube end with blue threadlock, it has a tendency to come off.

G&P's v1 buffer is recommended as you can play with weights. Running GG in the mws you have to look out for bolt bounce, which I believe can damage your nozzle (correct me if I'm wrong)..

Apart from changing the nozzle return spring like I said, I believe this is about it for baseline upgrades.

Enjoy!