Almost done!

Getting my chimney put in tomorrow just need to fill in with the cob but I have some last minute changes im concerned about. I had to turn my barrel/firebox to make the room easier to walk around and it has made it to where my barrel to manifold exit will have to have a imidiate 90° turn. Will that effect anything? I was planning to make it a 8inch exit and then reduce it to a 6 inch (size of my system) right after to give it more room to flow since it has to turn like that.

Not perfect. But some views and ideas.

https://permies.com/t/61657/Flue-exhaust-transition-plenum-pictures#546264

Usually, the plenum is considered good at.   3X the system size.