If you're looking at having this become much of a thing long-term, I'd highly recommend setting up occasional (once a week, once every two weeks, or something like that) GM-adjucated sessions of... some sort of episodic stuff in a more traditional RPG method of presentation. Possibly even as simple and generic/silly as "Random townsperson needs help with (rats/bandits/pests/chickens/cholera) causing problems with their (farm/workshop/store/brothel/evilcultishaltar)", and have a short little bout of investigation/roleplay/combat stuff. Tailor it to the player-driven RP that happens between those GM-adjucated sessions, if possible. It might not be exactly what you're looking for (and if it's not, feel free to completely ignore this suggestion!) but in my own experience, I've found a bit of GM-officiated guidance helps to keep people interested, and focused on RPing with one another.