Good stuff, re: the PR. I have since (my post), spent most of my Azure AD duties time not needing to worry about the newer things in the PS module. I've found that for reliability, as in things remaining preditcable and stable, MS Graph v1.0 directly (and Beta for some stuff although slightly contradictory to my predictable label) is the way to go.
While the PS modules are the wild west where anything can be done or changed, MS Graph is what vendors are given to rely on for the solutions and apps they develop. Thanks to that, MS Graph remains very predictable. Only issue is when a certain thing isn't yet supported in Graph. Then it's a waiting game where ETA's are hard to come by. But other than that, things sometimes are only doable there, and not available in the PS modules. An example is the LastSignInDateTime stuff. I believe it's now in the module, but had been available in MS Graph beta for quite some time first.