An update:
I’ve been getting builds that are appropriate to the state of the changes made now for just about 30 days. I’ve determined that the issue lay somewhere in the Intermediate/Build/Win64/… of the game project directory.
While I haven’t determined the specific cause, it appeared that a random file in that particular directories was changing and triggering a complete rebuild of the engine projects in that directory, basically ActorLayerUtilities thru WindowsMoviePlayer. It basically should be that once these are created, they should remain unchanged until there is a source change to those projects, and then at that, only the one in which the source changed.
So then, since I rebuilt the full engine as referenced above, only expected full game project builds have been triggered.
Unfortunately, I have not yet detected what is causing it, but I think if the issue starts again, then I’ll set up some monitors and note what could be acting on those files unexpectedly.\
Until then, I am marking this as resolved and hopefully it can be of assistance.