For example, machine augmented human (think weak AI + direct neural interface and all that cyborging whistles + mind drugs) might be quite likely to follow the FOOM

It seems unlikely to me. For one thing, see my Against Cyborgs video/essay. For another, see my Intelligence Augmentation video/essay. The moral of the latter one in this context is that Intelligence Augmentation is probably best thought of as machine intelligence's close cousin and conspirator - not really some kind of alternative, something that will happen later on, or a means to keep humans involved somehow.