Couple of design thoughts in no particular order (I'll also comment inline in the code where it makes sense and/or make a PR off this one):

• Is there a valid reason to use "None" on modern hardware?

• Perhaps we could simplify this to "Default" and "Subpixel" to be a little less technical; we don't really have to explain how anti-aliasing and subpixels work since users can choose it based on looks.

• I wonder if we should include a longer-form example in a card (or a stack of labels if that's needed) above these options for a better visual

• We could probably use an Infobar that appears on change to inform that apps will need to be re-opened to see changes, like we do in other plugs. This would clean up the amount of help copy.

• I think labels on the left should be top-aligned if we're going with vertical radio buttons

• We probably want to leave the subpixel settings visible but insensitive when unused so they don't seemingly randomly appear and change the flow of the page.

• We can probably drop "Text" from each of these labels since the whole page is about "Text"

• I wonder if a horizontal layout would work better for these radio options to take up less space?

• I wonder if these should be under their own subheading with an example? Let me prototype that up 😄