I have spent over a week now examining the fonts supplied by polymaker. See thing:13677 and thing:15710. The two openscad programs I used might be of interest to others. DroidSansMono_Regular_sphere.scad is an example of a program that writes a font on a sphere. Its a new version of the program described in thing:15710. Symbols were added and the characters moved further apart to take advantage of the large surface area of the sphere.

A second program, Quick_x2_DroidSansMono_Regular.scad, makes a quickly printed small sample of a font. Both programs can easily be changed to examine any of the available fonts.

I've looked at about 10% of the working fonts described by polymaker and have found three which seem complete: ArchitectsDaughter, DroidSansMono_Regular and DroidSerif_Italic. Their samplers are included below.

Many of the other fonts have only minor errors. For example DaysOne_Regular and Cabin_Regular have one of the o's in the percent sign filled in; that is a solid circle occurs rather than an open one. UbuntuBold_Italic and GloriaHallelujah have the capital O filled in while DroidSerif_Bold has filled spaces in the small a and small e. Filled in objects are a common problem; OpenSans Regular, Italic, and Semibold all have some filled letters.