On a phone the way it is implemented is not very convenient.
It happens many times I use this feature when I am playing because I like not having coordinates when I play so I have to toggle it back from where I left (reviews…) So functionality is pretty essential, to not lose time/ being distracted.
So what? Well most important is that you don’t see the board and the button at same time. And the toggle has 4 states. That mean you need scroll down, toggle, scroll up to the game to check and do this a few times until you reach what you want. ( Hopefully you didn’t miss and do all again).
If the button itself could indicate which state is active, that would be a way to avoid all these going up and down the screen. (And won’t change the global layout)