Appreciate the diagram Bill, but I think it gave me a flashback headache!

I find the Apple step/distance/flights recorder not all that accurate also. I started using an app called ViewRanger. It works pretty well for distance/elevation gain & loss and tracking. It seems to work without cell service but works best if you download maps of the area you're going to, beforehand.
Worked great for me last year coming down off a mountain and keeping me close to the route I took up. App is or was free, map downloading cost about $15 for a lifetime subscription. The key is keeping your phone charged, which I'm working on.