Yes, we stay both Deluxe and Moderate all the time, often on the same trip. We never stay Value due to bed size. And I know Pop has changed but even then the rooms are just too small. They were too small with Double beds so can't imagine the same rooms with Queen beds.
So we switch around all the time. On our next trip we are doing WL CL, POFQ, then BWI CL.
On other trips we've done CR, BW, POFQ, and on another we did YC, CC, then SSR (which is Mod if you ask me). Some others we've mixed on one trip, (in this order)
GF CL, POFQ
CSR, Poly
AKL CL, CBR
So as you can see, I don't think there's any rule about Mod then Deluxe or Deluxe then Mod, it all works for us.
We do it because we can. So many resorts, so little time. I can't ever decide where to stay so we stay in as many as we can. I think people put way too much on the status of labels of Deluxe vs. Mod. It's all Disney for goodness sakes. It's not like a Mod means you've gone slumming.