Grafista has glyphs with codepoints that are invalid Unicode codepoints e.g. Hex B0001 but which can't be rendered (they render as black boxes) by imagemagick using the pango renderer. Help please!

Anybody know how to render these non standard custom glyph’s like Grafista’s B0001 in a web app or in Python, Rust, Ruby etc. Ideally I’d render the custom glyphs to a PNG so I can make tshirts :-) !
Source for hex B0001 being an invalid Unicode codepoint (~~I thought it was invalid initially!~~) is Tim Bray’s blog post from August 14, 2023 (see also https://www.fileformat.info/info/unicode/char/b0001/index.htm which states: U+B0001 is not a valid unicode character.) :
```
The text must consist of a sequence of [Unicode scalar values]
(https://www.unicode.org/versions/Unicode10.0.0/ch03.pdf#G7404), 
i.e integers in the inclusive ranges 0-0xD7FF and 0xE000-0x10FFFF.
```
My toot about this:
- anybody know anything about custom fonts on Linux (ubuntu 22.04, on dell xps13) or macOS.? My plan was to use the cool graphic glyphs from the Grafista font and make a thunderbird infographic png out of text in Grafista. unfortunately although the font shows 1600 glyphs i only have access to 360 glyphs and xfd on linux shows the wrong glyphs, i.e. not the cool graphic glyphs