I hope console versions have button mapping.

This would be a nice addition. I find it odd that more console games don't do this.

Should be LAW to change into whatever button you want whatever action to be.

Stupid Flanders...

What? That's actually surprisingly simple. Compared to the work required for other mechanics, super simple.

It could work a little like:
You just make strings (labels) for all the buttons. A button would be "A". Right Trigger would be "RT".
Then you make variables for the buttons each action is assigned to.

var jumpbutton = "A"
var attackbutton = "X"
..etc

Then when the player changes it in the options, it changes those variables. Then when you create the procedure that handles the button prompt, it references that variable.

jumpButtonPrompt();
if(jumpbutton == "A")
img = A.png
if(jumpbutton == "X")
img = X.png

It's tedious, sure. But it's not even a day's work. An hour or two, tops. And that's an extremely rudimentary way of pulling it off with my limited scripting knowledge— I know there's other features like arrays and switch functions that can pull the above off faster, cleaner, and easier.

Not to sound like a know it all, but there really is no excuse for designers to leave out this feature. Its implementation is pretty easy.

Doing it in a local multiplayer situation (when there isn't a clear P1 and P2 side of the screen) can be complicated, but it's clearly not a situation Bloodstained would be tackling here.

In a single player experience, it's a pretty easy to handle, especially if they're following DRY code philosophy like they should be. Handling button prompts through procedures that you can make minor edits to when the situation arises simplifies the system quite a bit. Then you just go back and call that procedure and have it look up the player's settings when it needs to.

Yes, it's a whole lot better to start this system early than to go back and change all of your instances already layed out (though I'm not too sure how many button prompts Bloodstained will have outside of a tutorial regardless. Maybe in the command skill menu?), but this is something that should really be considered by all developers when starting a game project with the exception of unique circumstances. (Like, for example, Brothers: A Tale of Two Sons's control scheme is imperative to how the game delivers its narrative. I can't see that game being handled in any other way.)

Moreover, for there's always the slightly lazier method some games use (or at least, easier. Can't really call it lazy without knowing the circumstances behind the scenes), where they simply write something like
"Press the Attack Button (Default: X)"
In which case if the player never changed their controls, they now know to press the X button. And if they have changed the controls, then they should know better than anyone what the Attack button is.

Becomes a little trickier regarding things like overhead prompts, but you can viably use symbols that represent the commands as opposed to literal buttons on the controller.

To be fair, I'm sure this is all a lot easier when talking about a controller than say, keyboard controls though. But at the same time, I'd argue keyboard controls are the most important to allow reconfiguration for as well, because they're darn near impossible to fit to everyone's tastes.

Fair enough lol. And I never actually saw a QWERTZ keyboard before until I looked it up just now.
It's odd that it's basically the same thing but with Y and Z swapped. Wonder why that's a thing.