These things are true. The draw-through effect of long overlap cams does skew the relationship, and this effect itself changes with respect to rpm. Likewise, mechanical aspects such as compression ratio exert an influence, as to electronic aspects (fueling and ignition). It's easy to see that the relationship between load and torque is not linear, but it exists.

I'm not implying that it may be so easy, or even practical, but it is possible.

 

Most of you will NEVER be exposed to any cam timing that results in significant amounts of 'short circuit' (charge air out exh on overlap). Consider it a non-issue.

 

Perhaps largely a non-issue in rpm ranges where load is of interest anyway.