Be aware that all replacement text must be entered on a single line in the configuration screen. Although it can contain HTML which renders onto multiple lines, it is very limiting if you want to, for example, put a company address and contact details in a box and use it on multiple pages.
It would not take much to support milti-line replacement text IMO, perhaps using white space at the start of a line to indicate that it should be treated as part of the previous line.
I would love for the replacement text to work in text widgets too.