I think you keep yer feet totally on the floor on take-off. With all the bouncing around, you're going to hit the brakes inadvertently sometimes. If you abandon, with selecting idle and full reverse, you aren't going to get the brakes on as quick as autobrakes. Autobrake will give you full braking whereas whilst you are struggling to keep straight and cancel reverse if you start drifting, I'd be very surprised if you coould sustain maximum manual brakes. Make life easy- leave autobrakes on and take over when ready. But I have seen someone apply brake on take-off through lifting their foot up (nobody was aware at the time), and lost those tyres as a result