But they'd be doing a bridge descent even if enemies did continue to spawn. So I think it has to be said that the lack of enemies is really just a bonus, rather than being any part of the reason for doing it.

On another aspect, on Easy I don't think lack of enemies makes a whole heap of difference does it? Because they pose almost no threat. Maybe they can often be pretty much ignored on Normal too, but I'm not sure.

: and it's pretty much mandatory in MCC if you want the
: sub-3hr legendary time achievement for the campaign.

You sure about that? I'm just thinking, if you don't do a descent, how much time does it cost? You'd have to tackle covies for a while, but pretty soon you could reach a Ghost or hog, then whizz off to steal the platform Banshee, after which you could fly though pretty quick and get to the exit door at the twin bridges. Next you'll have some covies to tackle inside, but before long you'll be out the other side and can steal another Banshee, which can shortcut the remaining journey.

If this plan was performed fast, I wonder how the time would compare to a standard speed run time. Might it be a viable approach for that achievement? Or are things really too tight? In any case, it might make an interesting speed challenge.