Especially if you want to hide the rest of the text for a purpose, e.g. show the full text only to the paying customers.

I hadn't even considered that as a possibility! In this case, it is only to keep the amount of text short enough to get lots of entries on a page. The user can expand any they for which they want further information.

So, something like [% IF text.length > 150 %] - I can't see how to ensure the text is split on a word boundary with a simple IF condition.