Happy to see it works for you
It should HL your code when tab is reloaded, isn’t it working? I can make it works each time when you load documents from left pane, just like focus mode is updated each time, but with my current implementation when you have multiple scripts enabled then it will become laggy. I’m doing other things with scripting DL right now and I’m making some progress in understanding it in general, so I think in near future I will improve it to highlight code automatically each time.
My favourite theme is Twilight, but it’s not available in HL.js. Other than that, I can work with basically any theme with dark grey background, Monokai Sublime is pretty, Darcula too I’m using DL with dark theme, so I choose in HL.js also dark theme, but feel free to experiment what looks best in default for you