Hi !
Alex Chernovs design has only one outlet from the firechamber at the back, and it only has air intake at the back and in the front. This combined leads to a tendensy for the fire to draw out the back with out directly touching the coock top. It heats however ok, when it burns fully, but it is slow in the beginning and at the end since the fire is not forced close to the iron. If you want to use it a lot for coocking you can ad a crate in the middle, or redesign the firechamber with a baffel so that the fire neads to go to the frontand draw back across under the coock-top. This is what I did on my “Kitchen stove” Because of their constant desire to heat some food or simmer something this was a “dealbreaker” for them. For you it might not be so important. However, the bread oven works great, and heat is also great. You might be able to get the real drawings from Alex if you write him. This drawing might have design faults, it is defenently much larger because of the bricks adjusted size. Thanks for the tips about the grouping. You can see the inside using a tool called “section plane”