Domo Phoenix - Adjust chart font size

Hi all,

I'm currently developing an app that contains multiple Domo Phoenix charts, following along with this guide: https://domoapps.github.io/domo-phoenix/#/domo-phoenix/properties

I'm in the fine-tuning stage where many of the charts are created and the correct data is displayed, but the part that's stumping me is adjusting the chart properties. For each chart, there's a list of properties that I can assign to a chart. Here I'm looking to adjust the size of font in the category scale of a bar chart. On the corresponding Phoenix page, I see this as an adjustable property:

I'm setting up the properties of the bar chart according to the same page and many of them work such as label_text, hover_text, etc.:

The part that doesn't seem to work is when working with a datatype "select_list" property. I can't seem to find the correct string to set for the property nor the datatype if it's an enum or similar in any examples online or in the source code: https://github.com/DomoApps/domo-phoenix/tree/master
I caught something along the lines of font size being a string, either as "SMALL", "Small", or "small" at one point, but the phoenix library itself is intentionally scrambled (see lib/phoenix.js)

My question is then, for select_list properties, what is the format of strings or the datatype I should be using?