Microsoft Word has a great set of features called Auto Part and Auto Text. Does Writer have those features. They are a way to add text you put in a document over and over again. Like I object under due to ambiguity. Could be put in as @obj1. You would type that in and the word processor would finish. That is how Auto Text works. The Auto Part works in a similar fashion but allows to put formatted text you use over and over in a document. Like a signature block. Interested to see what can be done in LibreOffice along those lines.
The AutoText function is supported by LibreOffice writer. In the menu via Tools>AutoText... (Shift + F7) AutoText can be selected or new ones can be created. The individual texts can be assigned keyboard shortcuts.
For formatting text it is common and best to use stylesheets.
With me Win-10-1803-64-Bit, LibreOffice version 6.1.1.2- (64).
AutoText also supports formatted text: just select the formatted text in Writer when creating the AutoText.