Seems like it, yes: https://lansinggardendesign.com/blog/2020/9/6/arctostaphylos-bark

The old bark cracks into sections as the trunk expands. This ability to shed is part of the plant’s defense against insects and disease. When each year’s skin is shed, insects and disease are shed along with it. As opposed to the skin/defense of thicker, rougher bark, as most other plants have, Manzanitas are able to have the thin, sleek, smooth bark they are famous for.

Say, where can I get some of those square rocks, for uh, reasons?

My wife says it looks nothing like me, sorry I can’t help.