With kind permission from @LyricsLover, I've updated this with all current tag source commands and the format string functions for SayFormat/UseFormat. It should hopefully be usable in both Light and Dark mode.
I couldn't get [] working with the changes, though all the expected [Keys] are listed. Escaping certain characters isn't the best and Notepad++ does also breaks its own folding when a single json_foreach is contained inside an If ... Else/EndIf , i.e. containing the two ends of the loop within conditions.
I also made up a bracket checker based on this thread, it's handy for format strings when nested $if()'s get out of hand 
Please let me know if any of the changes are any help:
Notepad++ UDL v1.04.zip (4.0 KB)