Update: Scripture Forge now automatically uses the font specified in your Paratext project, if it is an SIL published font, or any of a number of other freely-licensed fonts. If you need a font that is not supported, please contact us.
Original answer:
There isn't currently a way to change the font, but we're open to providing a better font in cases where the default fonts are not sufficiently legible. What script is used in this project? Is there an SIL font that renders the project well? Could you also provide the Paratext project short name so I can look up the project? If your project is sensitive to share that way, you can private message me (click my name, then click send private message).