Now this blows my mind. I don't think that any airline's manuals nor Airbus manuals talk about messing with things like that during landing roll-out!!
And in the grand scheme of a successful and safe flight, trying to find the smoothest transisiton from auto to foot braking has very little importance, definitely not enough to make you try to develop your own little 'menu' of brake ops without knowing the exact technical intricacies of what this brake-by-wire system is exactlly doing at any given moment, this is just an incident waiting to happen, besides the distraction during such a critical phase of flight.
If you can't leave it alone, try it in the sim, with an engineer who knows what this brake system is doing. Either design a better system and propose it to the manufacturer or do what the system is designed for. Stick with your SOP.