I'm not sure I understand the question. Are you asking about the long-term therapeutic effects the regular high-dose psilocybin experiences? I cannot be certain. My only insight would be that it depends on what is taking place during these experiences.
This could be helped by setting up a hypothetical scenario. Say you are experiencing emotional problems, and seek out a therapist who will participate in guided high-dose psilocybin experiences with you. In such a state, my intuition is that cognitive, behavioral, and emotional therapy would be more effective, as you would have greater access to your higher cognitive processes. The fears and anxieties associated with the experience could be addressed and overcome, and the therapist could guide you into deeper and deeper therapeutic states. Theoretically, that is.
However, regularly dosing yourself with any tryptamine will result in tolerance if the doses are not properly spaced out. You'll find the substances grow less effective over time, and you need to take greater amounts to reach effective concentrations. The physical side effects alone could be very disruptive, even dangerous.
So I guess the questions are: How often would you be dosing? How large would the doses be? What would the set and setting be of these doses, and who else would be involved? What are your goals, what is driving you to pursue this?
I'm with you in being curious about this. My friend and I regularly do high-dose tryptamine psychedelic trips, sometimes spaced out by as little as a week, and I have no idea what the long term psychological effects of doing this are.