Difficult to set the profile banner

When I set the profile banner under User Profile it looks ok, but when I move to My Account the window size is different.  The profile banner is cropped.  Then it doesn't look centered.  I need to be able to move the image around like in User Profile while seeing it in the window size used in My Account.  Making me wait so long to update it isn't helpful either.  How am I supposed to remember exactly where I put it before after waiting so long before I try again?