Great job Chau!
RE: Smoke - from my limited experience with my WFO, the smoke is not a factor at all in stopping radiant heat from above. The only time there is much smoke anyway is when a new log is put on the coals. The reason you do not have enough radiant heat from above has to do with dome height and oven design (as far as neapolitan-style ovens go).
And once you have the oven going - at least in a round, neapolitan style oven - the coals are pushed to the right or left or INHIBIT the flow of air, and therefore heat, out the chimney. The heat rises up the rounded sides and flows back down. If the coals were in the back, then the heat would flow right out the chimney. This is something I learned here on the board in the first days of owning my WFO.