So, I'm slowly picking up the swipe up from the bottom to return to the Home Screen or select the App Switcher. Then I found the Accessibility settings for Tap on Back, so now a double-back-tap brings up the App Switcher. And while I was at it, a triple back-tap activates the Camera App.
I do need to make another hack at my center console tray on my Escape. I had to widen the notch when I went from the iPhone 5 to the iPhone 6 (the 8 had the same dimensions) and with the 13 being just the much wider, it's Knives Out time…
edit: I updated to iOS 15.0.1 which fixes the bogus "Out of Storage" warning on some iPhones (I had that on my iPhone 8 before I wiped it). Also, I just packed up my trusty iPhone 8 for its trip back to Apple. For some reason the return box took over a week via FedEx Ground to go from PA to IN.