Flags in open world
Option to turn off teardrop effects when not using the spyglass (really like the rain but for screens i would like to disable the droplets)
save/show the average price you have paid for your cargo
notebook (for own usage, maybe even tradable)
Spyglass at open sea
Navigation tools: draw lines and circles at the map, ruler to measure distance on map, compass in open world and map, a nomogram
edit: remove circle of death when pressing ctrl+h