The IGH isn't doing anything in 2nd gear.
It has no gears turning inside creating any additional friction at all, it's locked.
Only in gear 1 and gear 3 you have additional losses in the drivetrain compared to a purely derailleur based drivetrain.
I'm running a 58T chainring instead of a 52 chainring to keep myself in 2nd gear when cruising as this is the most efficient gear it has.
However my bike realy needs the lower gears when I'm not riding in flat terrain.
58:28 is too tall of a gear for climbing and larger cassettes mean I'll need a longer cage derailleur.
Longer cage+larger cassette mean the ground clearance starts to get dangerously low as this bike has 406 mm wheels with 28 mm tires.
Of course a front derailleur would be a better solution, but my frame can't fit one.
Conclusion:
Not much to gain by removing the IGH besides a slight weight reduction, but I'd lose my slightly less efficient climbing gears.
Anyway, this is a touring bike.
It's not a racing machine, it's priorises comfort over speed.
It is slower than my fairly aggressive road bike when I'm running it in a speed optimized setup. (UCI doesn't like that
)
If I wanted to optimize my recumbent for speed, I'd get a narrower seat at first because the current seat is wider than my upper body and creates more drag.
After that I'd run a rear shock with remote lockout.
Then I'd be looking at fairings, and if I run fairings, I'll need to keep the hub as 58:11 would be too short of a gear for topspeed and significantly larger chainrings aren't realy a thing.
But at that point this bike wouldn't be a good base for such a project.
It has small wheels, it's heavy, it has suspension and it's rather wide.
No amount of modifications would make it competitive with let's say a Milan SL or POB in therms of speed.