[abulman]

As I pointed out to the OP on Mastodon, I very much believe that it was a reference to Lawrence Livermore Laboratory, where they filmed a big door, and the original laser sequence from the first TRON movie.

LLL also made an in-house video when they were filming the original movie - https://www.spyculture.com/dept-energy-invent-making-video/

[OhMeadhbh]

sure, but when I worked there, the only abbreviation I remember seeing was LLNL for Lawrence Livermore National Laboratory. But the T:L producers could easily have just used LLL as their own abbreviation.