I wouldn't bother with AI content detection tools - they add an un-needed step to your workflow. You have no idea whether what they are looking at is anything like what Google is doing.
For those using AI content for a base for human writers - just add/edit what you feel is appropriate, check facts and correct them if needed, add whatever formatting you need. This is what the big sites do and they rank fine.
For those using AI content at scale for automated sites - introduce a few automatic filters. Rewrite randomly chosen sentences, add in a scattering of random spelling errors/typos, hell even run a simple synonymiser on some randomly picked words if you want (SEO going full circle). I'm sure the guys that used to do scraped and rewritten content at scale have their own old twists that they can reintroduce into their AI content workflows.