PyGMT: How to change Meca label sizes?

When plotting focal mechanisms with fig.meca, labels can be added above each beach-ball by including a label in the last column of the focal mechanism file that is being fed into the spec parameter. How do I change the size of the label text?

Currently, there is not a good way to my knowledge. Here is a workaround (warning: no guarantees that this will work in future releases, as it is not an intended use of the scale parameter):

fig.meca(spec="meca.dat", convention="aki", scale="1c+f36p,Helvetica,black")

I have opened a GitHub issue to add support for customizing the label appearance.