Having noticed that bit of unfinished business, I would like to add to this list. From the barrel, I have found the reigns and the spiked collar, and I have gotten to "free play" after becoming the Goblin King (I became the goblin king after sending to demonology studies twice) I would like to state that there is so much unfinished content and optional ending miss-outs that it really only makes sense to follow through to at least v1 completion.
There is a mention in the castle of expeditions, which could make for a wonderful Act VII intro, as well as the mention of a training academy for the maids, which could easily be tied in to the institute to form a "royal academy integration" in cooperation with both the institute and the madame, who would employ and fund students/graduates/trainees. This would also be a good tie-in for the spiked collar and pony-girls, along with the demonology outfit research (why is that option even there if you don't plan on using it?) As part of an agreement with the institute (perhaps a diplomacy quest or act could unlock it) you could even make it so that the girls can be sent for training to wear all sorts of outfits.
Putting the pony-girl reigns, spiked collars, possibly even gags in the unused headwear slot would simply make use of an otherwise unused feature and simply making everything available for all the girls would really give some true "epilogue" vibes rather than simply "free roaming" with all these unfinished bits and teasers staring me in the face.
I know you said this is the complete version, but please, even if you decide to take a break for a few months (ie. Put on hiatus for a refresher) since this really feels unfinished, and I'd love to see it pulled through to the end. Please come back to this later on and give a real finishing touch. You could probably bring this out to around ver.1.5 or so, with all the missing/unfinished content I saw in there... It would be a great leaning opportunity for you to figure out how to... "tie everything up" at the end of the game ;) so please consider it. For now I will simply watch your progress with the next game and what you're learning and doing from that.
PS. 7 months for a game this size is actually really impressive, despite the missing bits and bobs here and there, which I suppose might be due to you rushing the content instead of taking your time with it... really looking forward to future content from you dude! Great work!