Are the notches I'm seeing on the reverse (and maybe on the obverse) normal for some of these newer dimes? There seems to be a split on the top point of the 2 on the date, but I'm assuming that what I'm seeing is MD or DDD?
All Machine Doubling. Note all the areas you are looking at are affected on the outside edge of the devices and they contour was removed off that area. The DDRs are not on that area of the coin. On the single squeeze dies the design is in the central area of the coin.
Some are showing a widening EPUs.
But the outer areas are pretty much a waste of time on the single squeeze dies. Obverses on dimes are very few on DDO Dimes:
Take a look at the Variety Vista listings for the Roosevelt dime DDOs. Most do not have DDO's listed there or don't exist.