  Higgs Inflation via the unmodified metastable Standard Model Higgs Potential
is possible if the effective Planck mass in the Jordan frame increases after
inflation ends. Here we consider the predictions of this model independently of
the dynamics responsible for the Planck mass transition. The classical
predictions are the same as for conventional Higgs Inflation. The quantum
corrections are dependent upon the conformal frame in which the effective
potential is calculated. We generalise beyond the usual Prescription I and II
renormalisation frame choices to include intermediate frames characterised by a
parameter $\alpha$. We find that the model predicts a well-defined correlation
between the values of the scalar spectral index $n_{s}$ and tensor-to-scalar
ratio $r$. For values of $n_{s}$ varying between the 2-$\sigma$ Planck
observational limits, we find that $r$ varies between 0.002 and 0.005 as
$n_{s}$ increases, compared to the classical prediction of 0.003. Therefore
significantly larger or smaller values of $r$ are possible, which are
correlated with larger or smaller values of $n_{s}$. This can be tested via the
detection of primordial gravitational waves by the next generation of CMB
polarisation experiments.
