Dear Matthew,
I wrote you off the list in connection to the other thread where Hans helped me with using Roboto Flex.
I used your typescript definitions but the font is not embedded in the document.

** I've copied all the ttf font files to the recommended directory structure under: texmf-local/fonts/truetype.
** I've created a type-imp-roboto.mkiv file and saved it in the recommended location under: texmf-local/tex/.../mkiv/.
Using: \usetypescript or \usetypescriptfile or \usebodyfont [roboto] with setuphead does not work.

I use the following simplest setup command:
\setuphead[chapter][style={\switchtobodyfont[roboto,20pt]\ss}]

I will be glad to join forces and create the typescript file but maybe missing something obvious. While I could use an inline definition suggested by Hans in the other thread, Roboto is a great font and I or other people would like to use it as a shared resource.

All the best and thanks for help and feedback,
Pawel