In Docbook line breaks are achieved by literallayout element, where line breaks and white space in text are to be reproduced faithfully. This element is block level, appears in paragraph, contains text and inline elements and should affect both text directly inside if and text in contained inline elements.
Conversion does not implement this, meaning line breaks in text directly contained in literallayout will be respected, but not in the text inside contained inline elements.
Note: XmlText does not support line breaks in inline element text, only in paragraph text. Since we aim to cover only existing XmlText capabilities in first release of RichText, this can be fixed after migration from XmlText is done.