This is a thing that existed even when DS9 was being filmed; taking handwriting and converting it to printed fonts? It wasn’t as on the fly IRL, but by the 24th century I’m sure it would be perfect where you could write by hand and instantly have it transformed into print.
The Apple MessagePad did it on-the-fly, by the word. Problem was, it was terrible. It was supposed to learn your handwriting and get better over time, but it didn’t. The next to try was Palm, and they mostly got it with their special shorthand glyphs. I had both, and was much happier with my PalmPilots.