This is a good system and it is something I would absolutely love to see get a rework someday as it is now it is very easy to forget about and that is a shame as when I see it I see a lot of potential. if i recall correctly it was there since the beginning but hasn't changed at all since it was there besides the mine items. I bet with your new skills you could make it into an amazing.
My ideas involving this are such: que trade routes so you don't have to micromanage I think 5 would be a good starting point and it would work like with the research projects but the cost must all be put up in advance. Questline you can talk to merchants in the various towns to unlock new routes and do quests after a certain number of trades events will happen which will require your intervention or the vanguard forces and specific members like say a bandit raid is coming to pumu this raid will force Lili as the main leader or the academy which puts Owen and Wendy and Leneth on the front lines clearing events would increase the pool of results from trading (and give a reason to train less used vanguard forces). In the end putting effort could lead to CGs or possibly new skills or unique items for characters