Ah, I didn't realize you were only counting events eligible to be referenced in LD. But...
spoiler
I would be surprised if LD doesn't eventually reference things from season 2 of Picard, at least. Also LD could do their own time travel, so really everything is on the table.
725 + ST I-X
However, I did forget:
which brings it up to 800. Oops!
you also forgot PIC (30), PRO (20), and LD (32), so, 882 total to date.
Well, no episodes of Picard, or prodigy would be referenced in lower decks
Ah, I didn't realize you were only counting events eligible to be referenced in LD. But...
spoiler
I would be surprised if LD doesn't eventually reference things from season 2 of Picard, at least. Also LD could do their own time travel, so really everything is on the table.