Caravan Speed / Iroquois UA

How does caravan / speed distance affect gold income?

I was under the impression trade route gold yield is a function of resource diversity. So what is the benefit of Hiawatha's updated BNW UA of

Caravans move along Forest and Jungle as if they were Roads ??

Is it simply to remove them from danger more quickly to prevent plundering?

Roads increase the range or caravans

It's pretty minor, it just means they can travel farther, thus giving you more options of where to send one.

I wish it was: caravans are invisible to hostile units in forest. Imagine never losing a caravan to a barbarian in the forest. Ahh, so nice. Even juicier would be having all your units invisible to hostile units in forest, like subs. What were they thinking back in vanilla...

Though someone made a convincing argument that the forest-focus for Iroquois is backwards, that would still be a better iteration of the concept.

Invisible units in the Forrest would be a tab bit OP, so I doubt it'll be added, but invisible caravans seem ok.
However, I can help you if you want to use invisible units, the MSF mod allows you to upgrade some of your troops so they're invisible to all non-armored units and helis. I think you can see how that might be fun >;3