Ability to reassign footswitches

I want to be able to reassign a footswitch. At the moment I use footswitch E to send a midi message to stop and start the autoscroll on my iPad.
If I’m in scene mode and am on footswitch F, I might want to stop my autoscroll but I would have to press footswitch E which would be set up for a different sound. So I would like to be able to reassign footswitches so one just controls the autoscroll without affecting my scenes/patches.