Davo covered it pretty much. Mu cause of dirty glass was closing air too soon and subpar wood. You have 22% wood and it's not ideal but I understand there is no choice. Try to play with closing air later in burn. Your time will vary because everyone has different setup. Yeah, and don't expect flames going on for 5 hours, lot of hot coals keeping stove warm and cat working and it counts toward so called" burn " time.Not discouraged. I do like the heat output - it's incredible - and enjoy the beauty of the fires, especially when the combuster is engaged. Looks amazing. Just think for the price point, there should be zero issues. Having to make modifications to the design, although genius on your part, isn't something I expected. Now, so far so good for me. Cat seems to be working as advertised, no problem. Hopefully that continues, o/w I'm going to do what you did with the steel plate, although I'm leery. Is it working out for you?
Also, the glass on my unit gets real black every night. Haven't had any success burning it off with real hot fires. I like the glass clean and have been using a baking soda paste that works great, but wonder what your experience has been in this regard. I understand that as the fire burns out the glass can get dirty. Don't mind cleaning it, but wonder if there's any tricks to keeping it clean.
Happy New Year!