The Limit Line Length item is available via the Reformat Text button on the collection toolbar, except when the Recycle Bin tab is active.
Almost all Windows applications support automatic word wrapping, so there is no need to insert a line break at the end of each line. The key advantage is that the text will automatically rewrap when you edit it. However, some older applications do not support automatic wrapping, or do not support text containing very long lines or paragraphs. Use the Limit Line Length command to make AceText insert line breaks as needed, to accommodate such applications.
AceText will ask you for the maximum number of characters that any line may contain. Longer lines will be broken up by line breaks. AceText will make sure that words are not split up, so some lines may end up shorter than the length you specified.
If you select the option "justify between both margins", AceText will insert spaces into lines that are shorter than the number of characters you specified. The spaces will be inserted next to spaces that were already present in the original text. The inserted spaces will be spread out evenly across the length of the line. When the result is viewed with a fixed-pitch font such as Courier, the text will appear to be aligned to both the left and right margin. No spaces will be inserted into very short lines, since that would make them difficult to read. Such lines will remain short.
The Reflow Paragraphs item does the opposite, enabling you to comfortably edit text that was wrapped using line breaks, rather than automatic wrapping.
See Editing Clips and Text to learn how to use AceText.