Yes, very simple and it works.

Anyway, keep in mind that it applies to all factions, it can not be done only for Spaniards, and that limits the expansion of the AI. That is, it hurts the AI more than the human player, who more or less senses where the settlements are. It's probably the reason why they removed it.

If you still want to do it, replace /dlv_americas/data/world/maps/campaign/imperial_campaign/map_fog.tga with this file, remove (or backup) /dlv_americas/data/world/maps/base/map.rwm and start a new campaign.

https://drive.google.com/open?id=1fW...CvY7Uow7lDVxn_