So, I owe you guys an update today...
...the update is I'm maybe 3-5 hours of work from releasing a mod component replacing Gold Gifts with Investments, where you can give gold per turn to a city-state in return for influence return, with the gold per turn having concrete effects (granting them a military unit every few turns, or growing their city faster, or giving them money and production).
Just doing UI polish, tying up a couple loose ends (Quests and one Social Policy), notifications, and then I need to hook up the AI for it (but that's not very difficult, I promise), and it'll be ready to go. I'll start on the next Epochs version after that goes live.