Within the current version of magicplan it is, unfortunately, not possible to amend the font type. The font size can only be adjusted in “text box” from our Annotation objects.
You may choose to use the “text box” object to add a text to be displayed (e.g. instead of a room label) and then through the export settings choose what to be displayed and what not within the exported file.
It is worth to note, however, that the “text box” is indeed an object item. As such, it occupies a certain space onto the plan itself and the text within it will automatically populated the space accordingly. As such, you may choose to amend the size of the “text box” in the very same way you change the dimensions of any other furniture object which will also affect the way the text populates the space within the “text box” and then adjust accordingly.