I am on board with the idea of extracting as much heat as you possibly can.
If those pipes bent at right angles are chimney exhaust I can see they will be trouble spots with ash build up.
Just a matter of time of it doing this needing frequent cleanings, that kind of configuration will very quickly have ash build up which can and will effect drafting and even causing back drafting and smoke being pushed out the feed chamber area.
I as well had to accept short falls within my designs, mainly having to feed the stove every 45 minutes.
Depending upon what the wood condition that is available for him to burn will determine the rate of how often the system will require cleaning for optimum efficiency.
As drafting slows, so does efficiency drop.
Great attention needs to be directed at clean outs, and possible safety issues of clogging.
I have seen what I have just described in my own systems in this exploration.
Thanks for posting this COA...