Because this was intended to support `accelerate` and uses the variable-mode ad approach presented in 'the simple essence of automatic differentiation' which af

Because this was intended to support `accelerate` and uses the variable-mode ad approach presented in 'the simple essence of automatic differentiation' which afaik has not been implemented in conjunction with `accelerate` . (Your comment reads quite uncharitable/mean btw, hard to tell if it was intentional)