Let's just collect this in a thread for posterity.
Sewer Junction has a unique quirk where a Shield Bug is spawned in the ending trigger. This ending trigger (and only this one) is fired by any entity, not just marines. I've been told that it only fires once per second. If you manage to suicide just before the trigger fires, you can get a Mission Success without being in the end trigger. The previous Brutal ILs use this strat to save a second. But what has never really been clear is what the limit of this strat is.
Jhheight managed to get a suicide win from this far away, which is insane, it'd save several seconds to get it from this distance.
However, in my testing, I've found that the shield bug only appears at this distance: I don't know if it can still fire the trigger while it's culled but I'd assume it can't. I've done a lot of attempts getting the suicide win to work at this distance, but no successes. I'd always assumed the shield bug has to be aggroed to trigger the ending, but if that were true, jh's instance wouldn't be possible.
It'd be great if there were any way to properly debug how this mechanic works and what its limits are so we can properly strategize around it.