O2 accuracy with aggressive cam timing

We understand the nature of an O2 sensor is to recognize and reference oxygen content of exhaust. For that reason, anything that puts additional unused O2 in the exhaust stream, be it an exhaust leak, misfire, ignition cut rev limiter, OR a cam with excessive overlap, will cause the O2 sensor (NB or WB) to read leaner than actual. We also understand the importance of a reasonably close (read safe) A/F ratio, when using FI. In the interest of registering an accurate O2 reading, and using an LTx engine for reference, does anything has any input, in regards to, at what point, (cam timing and/or rpm) will cam overlap disrupt the accuracy achieved with a WB O2 sensor? Anyone?