Entertainment district related building, Enemy that capture your monster(some battlefuck will be nice) then bring it to their camp then u can rescue them, strong enemy faction that only use slaves pet etc, and more character customization really.
In the public version there's whole colony tiers without any additional buildings, so scope-wise expanding on buildings seems to be on the agenda. Bringing back enemy capture is something the dev is thinking about. Won't be easy to balance, though, and having to get back your fighters wasn't ever really the reason why you avoided kidnapping in EroDungeon, but them getting forced into cursed classes, halting progression in their actual class.
When it comes to lewdness -- big picture, there's not enough misfortune and predicaments (The series has always been primarily about kink and not sex). Part of that is due to principal design, not development status: In EroDungeons, cowgirls were a cursed class of humans, now it's... cowgirls. Maybe make the milk mage class uncursed for cowgirls, and maybe ramgirls, but cursed for any other it is even remotely applicable to (that is, any mammal).
There's quite a bit of design tension, here: Hunters is moving towards anno-style colony management, population-focused, economy-focussed, while much of Dungeons is about individual girls. It's absolutely possible to combine the two e.g. FreeCities did it quite well but that requires automation. There's certainly classes already in game which would make brilliant dominatrixes (e.g. latex mage, hypnomancer) with individual strengths and weaknesses (but all of them with the capability to boost compliance in an assigned girl but OTOH have service demands, both in infrastructure and from the girls (productivity)), and more than just one training building. Side note there should probably be a faction loyalty system in addition to raw compliance.
Dungeons also required you to constantly re-do your roster, while it's all too easy in Hunters to build up a squad that can take on anything (that's not necessarily a bad thing) but then have no incentive to actually get to know and get invested in the particularities of the rest of the girls. It becomes a game of min/maxing each girl for a particular role, once set, you can forget about them and often duplicate the relevant stats easily (if you have a pair of perfect genes waitresses, you have an infinite number of them, and latex and piercing manufacturing are all to easy to automate). In Hunters there's currently no incentive to pull girls out of production to fill a combat role, and the only reason my fighters occasionally end up in production is because their tiers (and general lack of allure genes) make them dominate at research.
Then, there's the dungeon experience itself: In Dungeons, you ended up picking up curses along the way. Yep, might end your run because your party becomes defunct and you need to forfeit (or risk kidnapping), but can also offer great boons -- or just replace a curse with a less annoying one. In Dungeons there were more reasons to enter a dungeon than to beat it.
My main gripes with the current state of colony management is the static frontline because defence is ludicrously cheap and effective: Just plop down outposts, done, you can switch to x9000 speed without anything happening, which then breaks a lot of other systems compared to Dungeons because there you couldn't just sit still and collect resources and fighting power. There's other bits and pieces but they seem to be largely addressed by the switch to more anno-style mechanics, though one final note there should be more mechanics to play tall instead of wide, things like upgrading pdoduction buildings / bonus building to have more worker slots. With all the stat maxing through genes and tiers the game wants you to play tall, but the colony buildings themselves lend themselves more to playing wide. Also, having a wide colony makes the girls anonymous, same old population vs. individual focus tension.
