Thanks. My concern here is potential difficulty moving back up when I'm ready, and having to explain it.

I did that and didn't find issue getting new jobs. The key is, because of the work is easy that I spent a lot of time learning new things and apply to my job. One of my previous job, I knew I was going to leave, but it was easy money so I did my job plus learned a lot of new things during that time. When I started job hunt, I had no problem getting interviews and offers.

I'm not suggesting you go from Senior Staff Engineer to Junior Developer. Instead, get a job where the work is something you know by heart.

Oh right, I understand now. That's a great idea to noodle about, thank you!