I can’t help but think there’s too much fire lit, and you’re choking the fire. I have no issues with opening my lid mid cook, with no temperature spikes. I have my controller set up, light a small amount of coals and close the lid. I’ll open the top a full turn, and monitor the temperature increase. Once the temp is within 50° of my set point, I’ll set the top just off the seat. You want the fan to work to keep temp where you want it. I simply don’t have the issues you’re describing, so I can’t help but think that there’s a set up issue. Sent from my iPhone using Tapatalk