Not an automatic way, but you can duplicate lines and then edit them individually. Not perfect, but better than nothing. To do that:

Open a syntax window (File > New > Syntax if you don't already have one open)

On the Edit Menu, select the keyboard shortcuts:

You could try COMMAND+U (For Windows, substitute CTRL for COMMAND for all of these, so CTRL+U on Windows) to duplicate the current line of a syntax file.

Not an automatic way, but you can duplicate lines and then edit them individually. Not perfect, but better than nothing. To do that:

Open a syntax window (File > New > Syntax if you don't already have one open)

On the Edit Menu, select the keyboard shortcuts:

You could try COMMAND+U (For Windows, substitute CTRL for COMMAND for all of these, so CTRL+U on Windows) to duplicate the current line of a syntax file.