I have had this issue for a while now. This is mostly when I want to read the results of the fit directly on my figure, or even to read the axis title. I just don't want to go through all the source code and remove the fontsize = 10 everywhere in order for spinmob to work normally on my machine.
This also doesn't only concern text but also the buttons being really small for the databox plot processor in the egg.gui.
I have found a way to work around this in Windows by just rescaling everything so buttons and all by the scale factor of the screen (which is normally in the settings) and even then I'm not super sure how easy this would be to change. The buttons issue is mostly when using mcphysics though.