Actually now that I think about it I have splashed Pirates CSG into other games.
The best one IMO has been Catan. If you have expansions, you can play a seafaring variant of Catan and a gold mechanic is introduced. I’ve played it but replacing their ship system with Pirates CSG ships. Ships cost one wood and wool per mast, and coins equal to their point cost. Crew also cost gold equal to points.
I’ve never expanded it beyond being an upgrade to the basic Catan game, but you could in theory make a megagame out of it, with your Catan cities producing ships which you then use to play Pirates CSG.