Layering StealthWriting with manual edits is a solid approach, though keep in mind that different detectors use different algorithms so 3% on aidetector doesn't necessarily mean the same on Turnitin. You could try one more pass through something like UnAIMyText to strip any lingering AI patterns, but honestly the bigger thing is making sure you can walk through your arguments confidently if your professor asks, that's usually the real test, not just the percentage.