[SBT]

Old printed books were normally limited to one font – many not even willing to incur the expense of italic and bold types. When transferring a book to the digital domain, I like to embellish the typography. One thing is finding nice fonts for headings and initial letters, but what about using different fonts within the text itself?
For example, when the text contains letters and other missives, what about rendering them in a handwritten font, with different fonts for each letter writer?
I have found few examples of fonts used as a literary device. Mark Twain uses it in "A Yankee at the court of king Arthur", where the hero uses German gibberish as magic incantations, and these are rendere as fraktur. Terry Pratchett uses it occasionally in his Discworld novels, notably a golem which "speaks" with a pseudo-hebrew font. And of course it is used extensively in comics; in "Asterix the Gaul" albums, goths speak in fraktur, vikings in pseudo-runes etc.
The standard argument against such font usage is that it contradicts the typographical dogma of maximum legibility. However, given judicious use, it seems unreasonable to let it trump all other considerations. If I may make the comparison to a book reading, it would be a very boring session if the reader gave exclusive priority to clear and unambiguous diction.
What views on this issue exists among my fellow readers and formatters?