Convert frequency units on sparameters object

I'd like to mitigate the amount of manual labour in formating my plots. I have 2-port touchstone file (.s2p) some of them are in Hz and some using GHz, but rfplot seems to default to Hz when I'd like to use GHz.

FileName = 'ArbitraryTouchstone.s2p';
S = sparameters(FileName);

rfplot(S, 1, 1);

I suspect there is an extra parameter, or maybe it can be with one or two lines of code to plot the data in GHz instead of Hz. I've seen FrequencyUnits properties for frd or writing, chgFreqUnit() for systems, but I'm not seeing the approach or equivalent for rf data or sparameter objects.

Thanks!