If you just wanted the loss, you could use:
val, grad = withgradient(loss, x, y, z)
which just does this:
val, back = pullback(loss, x, y, z)
grad = back(1.0) # or Zygote.sensitivity(val) instead of 1.0
To keep more things, you can extend this pattern:
(val, A, B), back = pullback(more, x, y, z)
grad = back(1.0)