Function command_draw_scope_retained 

pub fn command_draw_scope_retained(
    size: Size,
    recording: CommandRecording,
    out: Vec<DrawPrimitive>,
) -> DrawScopeDefault

The full retained form of command_draw_scope: the compact recording buffers and the materialization target both come back to the caller via DrawScopeDefault::finish, so a command re-recording every frame allocates nothing in the steady state.