Instead of just pasting the weapon sprite on top of the battler, this lets you customize the use animations to anything you want. Using the same names for Directions / Attacks section lets the engine automatically play the correct animation and use the correct sprite when using equipped weapon, but you can add more if you want something like movement animations outside battle (use normal sprite instead of battler lets you do that).
Often you want the same animations but different sprites for similar weapons (different bladed weapons, etc.). Just use the parent option in the database like before.
Making a CBS in RPG20XX is the optimal use case and you can do almost anything already. In the next release, it'll have the action RPG features required.
If you were talking about the default battle system, different layout modes is already planned. It is in a really basic GRID layout for now. Different default battle HUDs too.
Using a "Parallel During Battle" common event, you can draw on top of the battle for displaying additional stuff if you added a custom system or something. No more copying pages and pages of battle events, it's all quick an easy here and it uses the event scripting you're already used to.