it doesn't seem you can have more than 256 presets but 1 user text line can hold more lines of text meaning you can have a couple of sentence one beneath the other in 1 user text preset using returns

sometimes you will have to do corrections on the returns and used symbols if you copy past from word, ppt or ...

we did subtitles like that, needed to be in the screen because we needed a cinema effect, lots of work but worked well