Despite the disclaimer on the mod page regarding how little Caribbean Tales has been tested in the Maelstrom engine, as far as I can tell it works near perfectly, though I admit I have very little experience with the original game. The sole issue I've encountered is the non-functioning state of the "speak" feature while sailing next to other ships. You can select the option and select ships, but upon confirmation, nothing happens. As I said before, I have little experience with this game, so forgive me if I've merely missed an item required for the option, though I recall being able to communicate with ships since the beginning of the game.
Also forgive me if the functionality of Caribe Stories is a low priority (understandably so, as development of the Historical Eras mod appears to be the thing you enjoy most and the creation of your own game is likely more interesting than mere compatibility with older games) and this post is simply a nuisance.