Judy Mayberry posted this a couple of days ago. I thought I should repost with a solution for those experiencing the same issues.
I have an older Large Egg and when I added a new fire screen under the bottom vent cover, I had to pry the vent sliding channels out with a slot screwdriver, top and bottom, because the fit was too tight. Finally got it to work.
Last night I used the Guru adaptor on the vent to do my first overnight pork butt (I've always done them in the daytime) and at midnight in limited illumination I had the devil of a time closing off the adaptor with the vent door. I finally used the heat tape that Chubby gave Mickey who sent some to me, covered the open slot, and the butt was done late this morning.
I just went out there with a hammer and wide slot screwdriver to see what it would take to get the vent door closed. It took a lot! I pried out the sliding channels some more, banged into the right side of the adaptor (which knocks the sliding clip out of place...) with the slot and the hammer, and eventually got it closed.
The BBQ Guru is bendable. I had the same problem as you. My solution was to take the plate and put it in a vise. No need to clamp excessively. First remove the slider bar. Using only your fingers, bend the plate very slightly away from the fan holder. It doesn't take much.Move the whole thing up a little and do it again. Flip the Guru plate over and do the other side. You can also do this with the slider bar but be careful not to crush it flat in the vise. Mine now matches the curvature of the egg and fits perfectly behind the screen and damper doors.
I know the voices aren't real, but man, do they ever come up with some great ideas.