Seeking advice from Compiler farmers

My team has gotten to the point of doing the Compiler, but we're very inconsistent with the clear and it feels like it takes us 5 minutes or more when I can see teams 1 phase in under a minute

I have a couple questions that I'm hoping the Compiler farmers can answer for me

EMP nades. What exactly do they do? My team has been throwing them on the Compiler during DPS phase, but he still seems to spam summon balls, I thought it was supposed to stun it and extend DPS. Are we supposed to be throwing it on him BEFORE DPS and shield crack phase, does that work? We're getting shredded by balls during terminal phase, do we just need to get good?

Are the balls bugged? It feels like sometimes, the balls don't take any damage. Often, I realise it's because I'm shooting it from the side. Is this a case of server lag causing the balls to be further along than I think? In that case, should we ALL shoot our own balls that are chasing us, rather than assign one on ball duty?