Hi Bird, mate i have read all of your posts and webpages with great interest from day one
the proof of your sytem is also very evident in your imaging results - its an awesome system you have there, there is no question that it is a seriously effective set up. the only drawback I can see with the refrigeration device in a dob set up would be the extra weight hanging off the back maybe? But i love the concept of the unpainted aluminium tube, i had never heard that before - a very original idea!
I have always covered the smallish holes in the back of the mirror cell support after initial half hour - hour cooldown - on my 8" I use a shower cap - it is noticeable improvement of course and mandatory. It is a shame that these wonderful scopes have this problem - renderring them compromised quite often. your refrig. ideas are the best way i have seen so far of addressing this serious flaw in an otherwise near perfect design.
Cheers