Was looking for something exactly like this, I love what you have so far. I wanted another mechanic for players to be interested in besides the typical mine or craft!
Couple of suggestions - consider implementing a command to toggle the scoreboard (hud) display on or off? For players on the server who wouldn't actively be farming, or if a player is out mining. I know the config file has it for the overall server, but would be great if there was a way for individual players.
Currency tag/hook/whatever you call it - would love to use the currency for all players to use in custom shops or with custom wandering traders in addition to what you have planned!
Seasons Toggle - I'm a huge fan of Bokujo/Harvest Moon, so I love the complexity of farm sims with seasons etc. I'm trying to think for a whole of the server that it might be nice to be able to toggle them on or off, if most players find it too complex? However, I'm not sure if it's hardbaked into the crops code so might be too difficult.