I just wanted to thank TB here for sending out those samples... unfortunately the usps did a number on them but I think I may have two long enough pieces to make a short coil cover out of still. It is awesome that you were so willing to share out stuff to us and I really do want to thank you for that generosity, If I figure out anything or at least make a decently working one I will post info here after the weekend.
One thing I have seen relating to the drop in production once the top cap is on based on all the great posts here... since the main volume of vapor is forced out the top, and we seem to have the air holes super cooling that glass cover, I really think either moving the air hole up to meet the top of the glass, or doing a super short coil like I saw in an earlier post, may be a necessity to get these guys working well.
Just got my AGA Tiamat today and am looking forward to abusing it this weekend... great little device for the 22 bucks I paid!