Ok, I might be able to make this work for multi-register support:

```rust
    device.foo()
        .and(|d| d.bar())
        .and(|d| d.cow())
        .write(|(a, b, c)| {
            a.set_x(false);
            b.set_y(123);
            c.set_x(Cow::SomeValue);
        });
```

Yay, nay? Thoughts?