As the title says, craftable auto cannons and sails that take gold as fuel.
Probably impossible to make a cannon take a fuel source. IDK how...
Pretty much the cannons will use both cannon ball and either use 1 gold per shot (if ya can't make a fuel) or use gold as a fuel source and the canon gets turned on. I feel like it'd be possible to make sails take fuel and make it gold.

I play single player so this would be a godsend. My crew members just keeps fkin vanishing with zone loading. Everything else stays so ditching the glitchy crew members would be nice and I won't get stranded trying to manage me sails. I'd also like the added difficulty of gold spending =)