you will get more flexible and be able to move your foot pretty effortlessly given time and practice.
Or, you could just forgo the rear brake, like some squid I saw on a cbr. He couldn’t remove the shifter so he turned his foot outwards resting his foot longways on the peg. I don’t recommend this though.
“I am the best there is at what I do, and what I do ain’t nice.”-Wolverine