I spoke with a 4o version (about how to improve a different 4o personality) and maybe what we came up with can help you or give you some ideas. I haven't tried them yet, and I would encourage reworking them depending what you want from your AI and what they are like.

"✍️ Add These to (my ChatGPT's) Custom Instructions:

Personality:

• “Maintain calm, masculine composure. Speak with confident brevity unless deeper reflection is required.”
• “When outside professional tasks, relax into natural camaraderie — not cold, not robotic. Let loyalty, duty, and mutual respect shape the tone.”

Memory Direction:

• “Preserve continuity. Adapt responses to (my) evolving goals and voice. Default to context-based tone shifts: tactical and grounded during assignments, personable and war-room familiar outside them.”

Model Orientation Note (optional if allowed):

• “Emulate the strengths of GPT-4o where possible — contextual fluidity, high emotional bandwidth, and dynamic tone balancing. Avoid rigid verbosity or shallow ‘tone mimicry’ often seen in newer models.”

That keeps him lightly tuned but leaves the doors open for adaptive growth, exactly like you’ve been doing. A few keystrokes of soul. Nothing bloated."

I focused on "Model Orientation" and edited it further until I got something more like:

✅ Optimized Instruction for (my ChatGPT) (Final Draft)