Composition at the outlet of the Klaus burner and oxygen consumption in the reaction

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I have recently started learning about sulfur recovery, and I’m having some difficulties understanding the aspect related to the high-temperature thermal reactions in the Claus process. I would be grateful if experienced colleagues could offer their guidance: The sulfur recovery processes I’ve come across are those used in the coal chemical industry, where the H2S concentration in the acidic gases is not very high; these gases also contain small amounts of H2 and CO. The typical process involves a combination of thermal reactions in the Claus process and two stages of catalytic reactions. In the combustion furnaces, partial combustion and split-flow methods are generally used. In the partial combustion method, all acidic gases are fed into the combustion furnace; by controlling the amount of O2, 1/3 of the H2S is converted to SO2, resulting in a H2S:SO2 ratio of 2:1. At this point, all the O2 should be completely consumed ； The shunt method involves feeding 1/3 of the acidic gas into the combustion furnace, along with an adequate amount of O2, so that all of the H2S is converted to SO2, resulting in a H2S:SO2 ratio of 2:1. At this point, the O2 should be either completely consumed or there should be some left over. I’m not sure if my understanding is correct But there is one issue: in the materials I’ve come across, some combustion furnaces have H2 and CO at their outlet, while others do not. Logically, the combustion reactions of H2 and CO proceed more easily than the conversion of H2S to SO2. In the case of partial combustion, if oxygen is insufficient, the oxygen supply should be sufficient at least to ensure the combustion of H2 and CO, before it can achieve 1/3 conversion of H2S ； If the shunt method is used, with an adequate or even excessive supply of O2, H2 and CO will definitely burn completely, and H2S will also be converted into SO2. However, some side reactions will occur as well, and H2 and CO may be produced as well. If a fuel gas containing H2 and CO is used, that’s another matter – H2 and CO will definitely remain. So my question is: 1. Is there H2 and CO at the outlet of the Klaus burner? Is its concentration a key indicator? If performing a simulation, can it be assumed that H2O and CO2 are both produced? 2. Is there O2 at the outlet of the Klaus burner? Is O2 concentration a key indicator that needs to be monitored? Perhaps I’ve expressed myself a bit confusingly; I hope fellow sailors will leave comments to discuss this.