This has always been a slow burn game, and the unavoidable protracted update release schedule is a factor. Of course this schedule may also be decreasing the slow burn factor of the previous updates prior to the Patreon Purge.
Plus D is just entering into her new found world of sex. Elena has been flirting with her and gradually increasing D's openness to having sex with her. Even-though Elena has told the MC about D being into girls, D has to first admit she is sexually attracted to other girls, and then reveal the obvious to the MC. I would not be surprised if this happens in the next update.
IMO I think once D has had sex with the principle players there is going to be more variety of sexual liaisons. This is the final chapter so following normal story development action should pick up with D becoming more sexually active, then encountering an obstacle, then resolution.
End of Trilogy.