I think you might want to import an image for this, use Inkscape or a similar tool to create the exact face etching you have in mind and you should be golden :)
That's how I've been doing it, but it's a clunky work around to have to create an image and Photoshop and then individually adjust each face on each die that has the marker so it stays consistently spaced.
If you were able to shift enter on the text adjuster you could add the hash under the number the same way you can add any custom number or character. A toggle would be best but I'm not sure which would be an easier change.
Thanks again for the quick reply and tool!