I can try to answer any questions, but it doesn't seem like the 8bitdo Ultimate software is availible for download yet. Im not big into mechanical keyboards, this is actually my first, so I don't have much direct comparison experience to other keyboards.
but the buttons are big and f u n.
You accidentally made me realize something. The keypad would probably be better on the left than right. There's nothing to the left of most people's keyboards, and presumably you have your keyboard positioned in the best place for your hands regardless of keyboard layout. Shift the keypad, and other buttons, to the left instead of right would make more room for the mouse.
Edit: This is apparently already a thing, labeled as "left handed" for some reason. I'm not sure what being left/right handed has to do with it though because we all type with both hands already.
The point is that about 90+% of people can't use the numpad with their left hand.
And if you really, really want this feature, look for keyboards with detachable or separate numpads. Ages ago, I've seen such a thing where you had four modules that you could arrange in any order: Keypad, cursorpad, numpad, trackball. Today, you can easily get separate USB numpads.
i'm firmly of the belief that it's designed to be on the left
if you use a calculator with your left hand, A) your thumb (strongest digit) rests on
=(most used button), and B) you can write with your right handthen some wacko put it on the right of the keyboard, so enter is on your little finger and the mouse is miles away[^1] and now we have to live with the consequences
[^1]: yes i realise mouses weren't around when this layout was designed