Yeah, I don't want to revert either, but your point about the script triggers is a good one. Long, long, ago I had battled a BOB after I made it to the Spire and grabbed a Banshee, which made me think that proximity is a big factor. For the BOB that spawns closest, you've got to worry about Jorge alerting him, but the other two you can more or less ignore until you're more properly equipped, which is nice. That FRG is still pretty fierce.
In any case, I've got videos for the BOB at the first Tyrant gun (#27), the closest BOB in the Spire area (#28), and the BOB that spawns by where the Invasion generator is (#30). Once I get the far-left BOB (probably with a noob combo), and maybe re-do the video for #28 as it's ridiculously long, I'm going to do a run of the level on Legendary, with as few deaths as possible, killing everything, where no BOB spawns. Then I'll try to re-ignite the TotS BOB search, both here and maybe in a few other forums, if I can get people interested.
I've noticed that there are a few "doomed" Falcons on the level, in addition to the one at the very beginning, that will be taken out by the Tyrant guns unless you move very quickly. Not sure if that's part of this, but I'll try to save them in my run-through.