add a menu when you right click an object that has number inputs for x position, y position, width and height you could also compress some existing features into the right click menu
mockup

workaround:
just position the costume to the center, then change the x and y position of the sprite

NotK3ndricAltAgain wrote:

workaround:
just position the costume to the center, then change the x and y position of the sprite

problem with that: what about the width and also every time you set the position you have to remember the change also wouldn't work if you had more than 1 objects.