So I know option 2 is easier to code, so do your thang! But I also feel like option one sounds incredible! I feel like a lot of the pred scenes are pretty controllable, and thats fine. But adding a random element would be a bit exciting! especially if the onsen's give a legit buff that you want! like imagine you're currently controlling your lust for a vore job, and BOOM, a massive pred comes to make your life harder!
Whatever you choose, it will be amazing though! Your work is legit awesome and I cant wait for every update.