Cob Oven

Hi everyone,
I am revamping a cob oven and am inspired by the mini pizza ovens ooni makes. I want to make my cob oven so it has an area in the back for the fire that I can access from the back and so I don't need to wait for the cob oven to heat up. Do any of you have experience with cob ovens and know if this will work?

Those Ooni ovens look slick. I've made a long cob oven with a flat floor and a low dome with accessible openings in front and back: front for cool air intake and a slightly higher opening in back where smoke exits. To get the oven floor hot enough for crispy pizza the fire must be built on the cooking surface then banked to the side when the oven is hot. The low ceiling browns the top. One of my favorite inspirations for baking ovens is called, The Bread Ovens of Quebec. The book is a free download from the Canadian Museum of History:
https://www.historymuseum.ca/cmc/exhibitions/tresors/barbeau/mbp0501e.html
There is an oven in this book that has the double entry feature you are describing. For your pizza purposes, you will probably want to make a mini version that will heat faster with less wood.
Good luck with your project August!