Yes, I read it recently actually [The much shorter “exploring satipatthana” is the one i read ]. Ven. Analayo makes a really good point about this often repeated refrain:
In this way they meditate by observing an aspect of the body inside; they meditate by observing an aspect of the body outside; they meditate by observing an aspect of the body inside and outside.
So far, it seems to me that one of the ways body contemplation works is to break down the distinction between inside (my stuff) and outside (not my stuff). For example, there’s no difference between the heat in a radiator and the heat in my body; both intellectually and experientially both are just heat.
I treat my body as special, but on investigation there’s nothing about the nature of my body that justifies that. Like everything else, it’s just a clump of earth that is able to stick together for an odd 60-80 years (maybe) before it’s ground down to gunk and dust
In Ven. Analayo’s exploring satipatthana, he seems to interpret the arising and passing away as insights into impermanence.