They must have done this study into clozapine

How potent is the monthly blood monitoring? This trial could perhaps be done for patients new to clozapine. They'd be entered into a trial with 3 initial groups. One would be an atypical antipsychotic in injectible (depot?) form. The other would be a combination of medications designed at hitting the same neurotransmitters as clozapine.

All three would be adminstered as if they were clozapine. The second phase would be for non-responders who could be adminstered clozapine at three months into the trial if any of the other two groups fail. There'd be a TAU group where patients would be kept off clozapine for three months.

This isn't a totally pointless experiment. The reason is not to recommend blood monitoring if it proves to have a beneficial effect. It is to further evidence unexplained effects or at least effects of social contact and contact with medical personnel (which is my guess rather than the explanation for this hypothetical effect).