How to handle inter-subject scale difference in PSD/TFR


What is a common way to handle the difference in spectrum scales between subjects or sessions?
For instance with a TFR:

f, ax = plt.subplots(2, 1, sharex=True, sharey=True, figsize=(10, 5))
tfr1.plot(combine="mean", axes=ax[0], baseline=(2, 6), mode="percent")
ax[0].set_title("Subject 1")
tfr2.plot(combine="mean", axes=ax[1], baseline=(2, 6), mode="percent")
ax[1].set_title("Subject 2")

The color bar scales are different and make comparisons between subjects difficult. But at the same time, I don’t think using the same (vmin, vmax) across all subjects is correct. Maybe a normalization based on the total spectrum power at a given time? Or is this baseline sufficient?

Am I missing some argument/function implemented in MNE to do that?